An inner and outer double-layer nested pouring system for a special-shaped double-layer hollow thin-wall casting

Abstract

This invention discloses a nested gating system for irregularly shaped, double-layered, hollow, thin-walled castings, comprising an outer ring sprue and an inner ring sprue, both sharing a common runner. The runner is located at the bottom of the casting. An outer skin and an inner skin are located at the inner end of the outer ring sprue, with a hollow area between them. The inner ring sprue branches into a first ingate and a second ingate, which connect to the machined parts of the casting at a 45° angle to the horizontal. This system improves the filling efficiency of complex, irregularly shaped, double-layered, large hollow, thin-walled castings. It reduces cleaning difficulty, minimizes runner residue, ensures non-machined surfaces of the casting while reducing machining difficulty and time. Metal consumption is low, the gating system accounts for a small percentage of the casting weight, and material costs are saved.

Description

Technical Field

[0001] This invention belongs to the field of machining technology, specifically relating to an inner and outer double-layer nested gating system for irregular double-layer hollow thin-walled castings. Background Technology

[0002] Traditional slot gating systems are suitable for products with simple structures: Slot gating systems are typically suitable for simple rotating castings with wall thicknesses exceeding 10mm. However, for complex double-layered hollow thin-walled castings, incomplete filling or underfilling may occur. High metal consumption: The gating system is the same height as the casting, often resulting in a metal weight exceeding the weight of the casting itself. Difficult cleaning: Significant residue remains in the gating system increase machining workload; for complex castings, manual grinding and cleaning of residual gating channels are also required.

[0003] The traditional gating system design uses a plate-shaped ingate that connects to the entire height of the casting. This system includes a transverse runner, a sprue, and an ingate. The sprue is perpendicular to the transverse runner, and the ingate is attached to the sprue and connected to the casting, evenly distributed across the casting surface. This system is generally used for simple cabin-type castings.

[0004] Chinese invention patent CN110039031B discloses a device for casting bimetallic tube blanks. By controlling the casting sequence, casting speed, and mandrel diameter, it controls the structure, outer and inner diameters of the tube blank, as well as the thickness of the inner corrosion-resistant alloy layer, providing high-quality tube blanks for bimetallic metallurgical composite tubes. For bimetallic tubes requiring no further processing, one-time forming is also possible. Chinese invention patent CN114453559B discloses a delayed casting method for large castings, including determining the parameters of the ingate based on the casting structure and the required amount of molten iron, obtaining the original gating system, calculating the vertical height between the ingate at the lowest point and the ingate at the highest point, and calculating the time required for the casting to fill within that height. However, neither of these inventions solves the casting problem for irregularly shaped, double-layered, hollow, thin-walled castings proposed in this invention. Summary of the Invention

[0005] To address the aforementioned problems, this invention aims to provide an inner and outer double-layer nested gating system for irregularly shaped double-layer hollow thin-walled castings.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: an inner and outer double-layer nested gating system for an irregular double-layer hollow thin-walled casting, including an outer ring sprue and an inner ring sprue, the outer ring sprue and the inner ring sprue sharing the same horizontal gating, the horizontal gating being located at the bottom end of the casting, an outer skin and an inner skin being provided at the inner end of the outer ring sprue, with a hollow area left between the outer skin and the inner skin;

[0007] The inner ring sprue is divided into a first ingate and a second ingate, which are respectively connected to the machined parts of the casting and form an angle of 45° with the horizontal.

[0008] Preferably, the diameter of the outer ring sprue is smaller than the inner diameter of the inner ring sprue.

[0009] Preferably, the outer ring gating system fills the outer skin while simultaneously supplementing the inner skin with additional filling.

[0010] Preferably, the inner ring sprue fills the thin-walled hollow area of ​​the large unmachined surface inside the casting.

[0011] Preferably, a riser is provided at the upper end of the inner ring sprue, and the riser is higher than the second ingate.

[0012] Preferably, the inner ring sprue does not contact the non-machined surface of the casting.

[0013] Preferably, the gating system is not at the same height as the casting.

[0014] Compared with existing technologies, this invention has the following advantages: The inner and outer ring sprues share the same runner, resulting in a smaller weight proportion of the gating system. The outer ring gating system fills both the outer and inner skin simultaneously. The inner ring gating system's sprue has two ingates that connect to the machined parts of the casting at a 45° angle to the horizontal, increasing the net flow rate of the molten metal and enabling rapid filling of thin-walled areas. The raised sprue acts as a riser to compensate for shrinkage in the casting area. The inner ring gating system does not contact the non-machined surfaces of the casting, reducing the weight proportion of the gating system and meeting the technical requirements for non-machined surfaces of the casting cavity while reducing machining time and difficulty. This system improves the filling efficiency of complex, irregularly shaped, double-layered, large, hollow, thin-walled castings. Cleaning is easier, reducing gating residue and ensuring the non-machined surfaces of the casting while reducing machining difficulty and time. Metal consumption is low, the gating system's weight proportion is small, and material costs are saved. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the specific embodiments of the present invention, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a diagram illustrating the internal and external double-layer nested casting system of this invention.

[0017] In the diagram, 1-outer ring sprue; 2-outer skin; 3-first ingate; 4-second ingate; 5-inner skin; 6-riseer; 7-inner ring sprue; 8-sprue. Detailed Implementation

[0018] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. However, it should not be construed that the scope of the subject matter of the present invention is limited to the following embodiments. All modifications, substitutions and alterations made based on ordinary technical knowledge and common practices in the art without departing from the above-described technical concept of the present invention are included within the scope of the present invention.

[0019] Reference Figure 1 The gating system includes an outer ring sprue 1 and an inner ring sprue 7, which share the same horizontal runner 8. The horizontal runner 8 is located at the bottom of the casting. An outer skin 2 and an inner skin 5 are provided at the inner end of the outer ring sprue 1, with a hollow area between the outer skin 2 and the inner skin 5. The inner ring sprue 7 branches into a first ingate 3 and a second ingate 4, which are respectively connected to the machined parts of the casting and form an angle of 45° with the horizontal.

[0020] This invention provides a nested double-layer gating system, designed to address the high technical requirements and structural characteristics of complex, irregularly shaped, large, hollow, thin-walled castings, reducing the number of machined areas within the casting cavity. The inner gating system fills the large thin-walled area, while the outer gating system fills both the outer and inner skins simultaneously. Based on the casting's structure and material characteristics, this gating system ensures relatively smooth filling and minimizes cavity erosion and the likelihood of air entrapment.

[0021] The inner and outer rings share the same gating system, reducing the number of gating systems. The inner ring gating system fills large thin-walled areas, while the outer ring gating system fills the outer skin and supplements the inner skin.

[0022] The inner ring gating system's sprue branches into two ingates that connect to the machined parts of the casting, forming a 45° angle with the horizontal. This increases the net flow rate of the molten metal, allowing for rapid filling of the thin-walled inner area. The purpose of this is to reduce the contact area between the gating system and the casting while increasing the amount of molten metal input, thus enabling the molten metal to quickly fill the thin-walled area.

[0023] Simultaneously, the raised portion of the sprue serves as a riser to compensate for shrinkage in the casting area. This gating system is not at the same height as the casting, reducing the contact area between the sprue and the casting, minimizing sprue residue, and lowering the weight ratio of the gating system. This satisfies the technical requirements for non-machined surfaces within the casting cavity while reducing machining time and difficulty.

[0024] Example: This invention designs a double-layer nested gating system for complex, irregularly shaped, double-layered, large, hollow, thin-walled castings, which includes: an outer Φ75 sprue 1, an outer skin 2, a first inner gate 3, a second inner gate 4, a 3mm thick inner skin 5, a riser 6, an inner Φ80 sprue 7, and a 60*60 cross-sectional area horizontal sprue 8.

[0025] The outer ring sprue 1 and the inner ring sprue 7 share the same horizontal runner 8. The inner ring sprue 7 fills the thin-walled area 5 of the large non-machined surface. The outer ring sprue 1 fills the outer skin 2 and supplements the inner skin 5 at the same time. The inner ring sprue 7 is divided into a first ingate 3 and a second ingate 4, which are connected to the machined parts of the casting respectively and form a 45° angle with the horizontal. This can increase the net flow rate of the molten metal and quickly fill the thin-walled area. At the same time, the sprue 6, which is higher than the second ingate 4, serves as a riser to feed the casting area.

[0026] The foregoing has provided a detailed description of the inner and outer double-layer nested gating system for irregularly shaped double-layer hollow thin-walled castings provided by this invention. Specific examples have been used to illustrate the structure and working principle of this invention. The descriptions of the embodiments above are merely for the purpose of helping to understand the method and core ideas of this invention. It should be noted that those skilled in the art can make various improvements and modifications to this invention without departing from its principles, and these improvements and modifications also fall within the scope of protection of the claims of this invention.

Claims

1. A double-layer nested gating system for irregularly shaped double-layer hollow thin-walled castings, characterized in that: It includes an outer ring sprue (1) and an inner ring sprue (7). The outer ring sprue (1) and the inner ring sprue (7) share the same horizontal sprue (8). The horizontal sprue (8) is located at the bottom of the casting. An outer skin (2) and an inner skin (5) are provided at the inner end of the outer ring sprue (1). A hollow area is left between the outer skin (2) and the inner skin (5). The inner ring sprue (7) is located inside the inner skin (5). The inner ring sprue (7) is divided into a first ingate (3) and a second ingate (4) arranged vertically and vertically, which are connected to the machined parts of the casting respectively, and form an angle of 45° with the horizontal. The outer ring sprue (1) fills the outer skin (2) and also supplements the inner skin (5). The inner ring sprue (7) fills the thin-walled hollow area of ​​the large non-machined surface inside the casting. The inner ring sprue (7) does not contact the non-machined surface of the casting. The height of the inner ring sprue (7) is lower than the height of the casting.

2. The double-layer nested gating system for irregularly shaped double-layer hollow thin-walled castings according to claim 1, characterized in that: The diameter of the outer ring sprue (1) is smaller than the inner diameter of the inner ring sprue (7).

3. The double-layer nested gating system for irregularly shaped double-layer hollow thin-walled castings according to claim 1, characterized in that: A riser (6) is provided at the upper end of the inner ring sprue (7), and the riser (6) is higher than the second ingate (4).

Images