A string-bead type group tree structure and a method for optimizing a complementation path

Abstract

The application provides a kind of string bead type group tree structure and shrinkage path optimization method, it is related to investment precision casting technical field, it is applicable to impeller, blade, compressor rotor and other high-precision complex casting investment casting.The group tree structure is connected by a plurality of wax patterns through die head and spherical shrinkage wax block, and the quick and stable connection between the wax patterns is realized through the buckle structure arranged on the shrinkage wax block.The die head, wax pattern and wax pattern are connected by plug-in buckle, which improves the assembly efficiency and structural stability.The wax pattern, die head and shrinkage wax block are 3D printed by PLA material, which has high precision, good debinding performance, environmental protection and other advantages.The two ends of the module are provided with M16 threaded holes, which is convenient for operation with automatic equipment.Through optimizing the distribution and quantity of shrinkage wax block, the metal liquid shrinkage path is prolonged, which effectively reduces the casting shrinkage hole, shrinkage and other defects, improves the casting yield and consistency, and has good process adaptability and application prospect.

Description

Technical Field

[0001] This invention relates to the field of investment casting technology, specifically to a beaded tree structure and a feeding path optimization method, applicable to the wax pattern manufacturing and casting process of high-precision complex castings such as impellers, blades, and compressor rotors. Background Technology

[0002] In investment casting, the wax pattern tree is the core structure for simultaneously casting multiple parts. Current technologies mostly use hot-melt welding with a soldering iron to fix the wax pattern to the main mold frame, forming an integral tree structure. However, this method has the following problems: unreasonable feeding path design leads to casting defects such as shrinkage cavities and porosity at the far end; the overall integrity of the welded mold frame is too strong, lacking modular and standardized design, limiting production flexibility; manual hot-melt welding of each piece with a soldering iron is labor-intensive and inefficient; the wax pattern is prone to deformation during the welding process, making it difficult to meet the manufacturing requirements of high-precision and complex castings; incomplete degreasing or residue of material affects the surface quality of the mold shell; and poor compatibility with automated equipment limits the development of intelligent casting.

[0003] Currently, most publicly available patent documents still primarily describe wax pattern assembly trees as individual or arranged welded components of a single mold frame, resulting in low manufacturing efficiency, poor structural flexibility, and insufficient standardization. Therefore, there is an urgent need for a compact, rationally designed, and easily manufactured wax pattern assembly tree structure and its optimization method to improve casting efficiency, casting consistency, and yield. Summary of the Invention

[0004] In view of this, the present invention aims to propose a beaded tree structure and a method for optimizing the shrinkage path, so as to solve the problems of low manufacturing efficiency, poor structural flexibility and insufficient standardization of wax model tree assembly in the prior art.

[0005] To achieve the above objectives, the technical solution of the present invention is implemented as follows:

[0006] A beaded tree structure, comprising:

[0007] Multiple wax models, wherein the multiple wax models are arranged in parallel;

[0008] A shrinkage-compensating wax block is placed between two adjacent wax molds or at the top of the wax molds to form a shrinkage channel for the molten metal.

[0009] The mold head is located at the top or bottom of the entire beaded tree structure. The bottom mold head is connected to the wax model, and the top mold head is connected to the wax model through the shrinkage-compensating wax block. The wax model and the mold head are connected by a snap-fit ​​structure, which is set on the shrinkage-compensating wax block. The wax model is connected by the mold head or the shrinkage-compensating wax block to form a "beaded" arrangement structure.

[0010] In some embodiments, the wax model, mold head, and shrinkage-compensating wax block are all 3D printed using PLA material.

[0011] In some embodiments, the shrinkage wax block is spherical.

[0012] In some embodiments, the diameter of the spherical shrinkage wax block is 40-80 mm.

[0013] In some embodiments, threaded holes are provided on the mold heads at both ends of the beaded tree structure.

[0014] In some embodiments, the plurality of wax molds are evenly distributed along the central axis and are arranged in parallel vertically, with the distance between two adjacent wax molds being 40-80 mm.

[0015] In some embodiments, the tree structure is suitable for investment casting of titanium alloys, high-temperature alloys, or stainless steel.

[0016] This invention also provides a method for optimizing the shrinking path of a beaded tree structure. Using the beaded tree structure described above, the method includes the following steps:

[0017] Optimize the position and quantity of spherical shrinkage-compensating wax blocks based on the geometric dimensions and spacing of the wax model;

[0018] The snap-fit ​​structure allows multiple wax molds, mold heads, and spherical shrinkage wax blocks to be quickly assembled into a beaded tree structure.

[0019] The assembled tree structure is degreased and fired to form a casting mold;

[0020] The molten metal is poured in to complete the casting process.

[0021] In some embodiments, during the degreasing step, the PLA material is completely volatilized without any residue.

[0022] In some embodiments, the molten metal is a titanium alloy or a high-temperature alloy, and the casting is used to manufacture impellers or aero-engine blades.

[0023] Compared with existing technologies, the beaded tree structure and path reduction optimization method described in this invention have the following advantages:

[0024] Using PLA material for wax model manufacturing offers excellent degreasing properties, allowing for complete evaporation without residue, thus preventing contamination of the mold shell surface. It also boasts high printing precision, enabling the creation of wax models with complex geometries. Furthermore, its high surface finish facilitates shell making and demolding processes. Additionally, PLA is an environmentally friendly material, aligning with the trend of green manufacturing.

[0025] The beaded structure and modular snap-fit ​​connection enable rapid assembly and flexible configuration of the wax pattern tree, significantly improving casting efficiency. Combined with a spherical feeding wax block design, the metal molten material feeding path is optimized, effectively reducing casting defects such as shrinkage cavities and porosity, thus improving casting quality and yield. The wax pattern tree structure is stable and easy to operate, suitable for manufacturing wax patterns for high-precision, complex castings such as impellers, blades, and compressor rotors. The M16 thread design enhances compatibility with automated equipment, improves process integration and intelligence, and has promising prospects for widespread application. Attached Figure Description

[0026] Figure 1 A comparison diagram of the tree structure of a traditional wax model assembly;

[0027] Figure 2 This is a schematic diagram of the overall structure of the wax model tree described in this invention;

[0028] Figure 3 This is a schematic diagram of the snap-fit ​​structure described in this invention;

[0029] Figure 4 This is a physical image of the snap-fit ​​structure on the spherical shrinkage-compensating wax block described in this invention;

[0030] Figure 5 This is a physical image of the M16 threaded hole described in this invention.

[0031] Explanation of reference numerals in the attached figures:

[0032] 1-Wax model, 2-Shrinkage wax block, 21-Snap-fit ​​structure, 3-Mold head, 31-Threaded hole. Detailed Implementation

[0033] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0034] This invention provides a beaded tree structure, such as... Figures 1-5 As shown, a beaded tree structure based on PLA 3D printing and snap-fit ​​connection is illustrated, wherein the wax model beaded structure includes:

[0035] Multiple wax molds 1 are arranged in parallel. The wax molds 1 can be impellers, blades, rotors, etc., and are connected in series by mold heads or shrinkage wax blocks to form a "beaded" arrangement structure.

[0036] The shrinkage-compensating wax block 2 is placed between two adjacent wax molds 1 or at the top of the wax mold 1 to form a shrinkage channel for the molten metal;

[0037] The mold head 3 is located at the top or bottom of the entire wax model beaded structure. The bottom mold head 3 is connected to the wax model 1, and the top mold head 3 is connected to the wax model 1 through the shrinkage-compensating wax block 2.

[0038] Snap-fit ​​connection structure: The wax model and the mold head are connected by snap-fit. The snap-fit ​​structure 21 is set on the shrinkage-compensating wax block 2, rather than the wax model body.

[0039] PLA material 3D printing: The wax model 1, mold head 3 and shrinkage compensation wax block 2 are all 3D printed using PLA material, which has high precision, high surface smoothness and good degreasing performance.

[0040] In some embodiments, the feeding wax block 2 is spherical, which increases the diameter of the molten metal feeding channel, optimizes the molten metal feeding path, and effectively reduces casting defects such as shrinkage cavities and porosity. Further, the diameter of the spherical feeding wax block 2 is 40~80mm, preferably 50mm.

[0041] Both ends of the wax model assembly tree have M16 threaded holes 31 on the mold heads 3, which facilitates connection with handles or automated equipment.

[0042] Compensation path optimization: Based on the geometric dimensions and spacing of the wax model 1, the position and quantity of the spherical compensation wax blocks 2 are optimized to improve compensation efficiency. In some embodiments, multiple wax models 1 are evenly distributed along the central axis and are arranged vertically parallel to each other, with a distance of 40~80mm between two adjacent wax models 1.

[0043] Modular and rapid assembly: The modules are quickly assembled by snap-fit ​​connection, improving production efficiency and process adaptability.

[0044] The above method is applicable to the casting of high-precision impellers, blades, rotors, etc., made of titanium alloys, high-temperature alloys, or stainless steel.

[0045] This invention significantly improves the manufacturing efficiency, feeding effect, casting consistency, and yield of wax pattern assembly through innovative methods such as modular wax pattern structure and snap-fit ​​connection, spherical feeding wax block design, PLA material 3D printing, and M16 thread standardization design. It is suitable for investment casting of high-precision complex castings.

[0046] Example 1: Multiple titanium alloy impeller wax module trees (size: Φ207mm×60mm)

[0047] (1) Structural design: Three impeller wax molds are set on each wax mold group tree. The wax molds are evenly distributed along the main trunk direction, and the spacing is set to 60mm to ensure that the molten metal can be evenly distributed and effectively compensated during the pouring process.

[0048] (2) Optimization of the shrinkage compensation structure: A spherical shrinkage compensation wax block with a diameter of 50 mm is set between adjacent wax models. The spherical shrinkage compensation wax block can effectively extend the shrinkage compensation path and improve the shrinkage compensation effect of the molten metal in the far-end wax model area.

[0049] (3) Snap-on connection structure: The snap-on connection structure is adopted, and the snap is set between the spherical shrinkage wax block or the wax block and the mold head, so as to realize the fast, stable and detachable assembly between wax molds or wax molds and the mold head, thereby improving the assembly efficiency and structural stability of the wax mold tree.

[0050] (4) PLA material 3D printing manufacturing: The wax model, mold head and shrinkage wax block are all made of PLA material through 3D printing technology. It has the advantages of high precision, good surface quality and strong designability, and is suitable for the wax model manufacturing of complex castings.

[0051] (5) Modular and standardized assembly: The modules are assembled in a modular manner through a snap-fit ​​structure, which enables the rapid assembly and flexible configuration of the wax model tree, greatly improving production efficiency and process adaptability.

[0052] (6) Tapping design and automation adaptation: M16 threaded holes are provided at both ends of the tree to facilitate use with handles or automated fixtures, thereby improving the ease of operation and the level of process automation.

[0053] (7) Casting and testing process: The wax model tree is degreased and baked to form a mold; titanium alloy molten metal is poured to complete the casting process; the casting is dimensionally scanned and non-destructive tested to verify the internal and external quality of the casting.

[0054] Actual casting verification shows that the casting effect is significantly improved after adopting the wax pattern tree structure and shrinkage compensation optimization method described in this invention: shrinkage defects are reduced by about 80%; the casting yield is increased to 92%; the wax pattern replacement efficiency is increased by more than 50%; and the structural stability and assembly convenience are significantly better than traditional welded structures.

[0055] Example 2: Wax model tree of aero-engine blade (800mm×350mm)

[0056] Structural design: A single-piece arrangement is adopted, with the mold head and wax model connected by a plug-in snap-fit; shrinkage-compensating spherical wax blocks are set on the top and sides to achieve multi-angle shrinkage optimization;

[0057] 3D printing wax molds, mold heads, and shrinkage-compensating wax blocks; PLA material ensures high precision and degreasing performance.

[0058] M16 thread is compatible with automated fixtures, improving operational efficiency.

[0059] Casting effect:

[0060] Shrinkage porosity and shrinkage defects are significantly reduced, and the yield rate is increased to 93%; the pass rate of X-ray inspection is improved, meeting the aerospace-grade casting standards.

[0061] While the present invention has been disclosed above, it is not limited thereto. Any person skilled in the art can make various modifications and alterations without departing from the spirit and scope of the invention; therefore, the scope of protection of the present invention should be determined by the scope defined in the claims.

Claims

1. A beaded tree structure, characterized in that, include: Multiple wax models (1) are arranged in parallel. The shrinkage-compensating wax block (2) is placed between two adjacent wax molds (1) or at the top of the wax mold (1) to form a metal liquid shrinkage channel; The mold head (3) is located at the top or bottom of the entire beaded tree structure. The bottom mold head (3) is connected to the wax mold (1), and the top mold head (3) is connected to the wax mold (1) through the shrinkage wax block (2). The wax mold (1) and the mold head are connected by a snap-fit ​​structure (21). The snap-fit ​​structure (21) is set on the shrinkage wax block (2). The wax mold (1) is connected by the mold head or the shrinkage wax block to form a beaded arrangement structure.

2. The beaded tree structure according to claim 1, characterized in that, The wax model (1), mold head (3) and shrinkage wax block (2) are all 3D printed using PLA material.

3. The beaded tree structure according to claim 1, characterized in that, The shrinkage wax block (2) is spherical.

4. The beaded tree structure according to claim 3, characterized in that, The diameter of the spherical shrinkage wax block (2) is 40~80mm.

5. The beaded tree structure according to claim 1, characterized in that, The molds (3) at both ends of the beaded tree structure are provided with threaded holes (31).

6. The beaded tree structure according to claim 1, characterized in that, The multiple wax molds (1) are evenly distributed along the central axis and are arranged in parallel vertically, with a distance of 40~80mm between two adjacent wax molds (1).

7. The beaded tree structure according to claim 1, characterized in that, The tree structure is suitable for investment casting of titanium alloys, high-temperature alloys, or stainless steel.

8. A method for optimizing the path reduction of a beaded tree structure, characterized in that, Using the beaded tree structure as described in any one of claims 1 to 7, the path reduction optimization method includes the following steps: Optimize the position and quantity of spherical shrinkage-compensating wax blocks based on the geometric dimensions and spacing of the wax model; The snap-fit ​​structure allows multiple wax molds, mold heads, and spherical shrinkage wax blocks to be quickly assembled into a beaded tree structure. The assembled tree structure is degreased and fired to form a casting mold; The molten metal is poured in to complete the casting process.

9. The path shortening optimization method according to claim 8, characterized in that, During the degreasing step, the PLA material completely evaporates without leaving any residue.

10. The path reduction optimization method according to claim 8, characterized in that, The molten metal is a titanium alloy or a high-temperature alloy, and the casting is used to manufacture impellers or aero-engine blades.

Images