A lost foam casting structure for large-diameter cast iron pipes

Abstract

This utility model discloses a lost foam casting structure for large-diameter cast iron pipes, comprising a circular lost foam casting mold with a supporting skeleton inside. The supporting skeleton has a central ring, and two layers of supporting rods extend radially outward from the outer wall of the central ring. Both the upper and lower supporting rod groups are composed of several supporting rods, with one end of each supporting rod connected to the outer wall of the central ring and the other end connected to the inner wall of the circular lost foam casting mold. Furthermore, this utility model includes several V-shaped diagonal braces between the upper and lower supporting rod groups. The design of the V-shaped diagonal braces better supports the middle position of the circular lost foam casting mold, effectively reinforcing even the vulnerable parts in the middle of the lost foam casting mold, thus increasing the mold's compressive strength.

Description

Technical Field

[0001] This utility model relates to the field of lost foam casting technology for cast iron pipe production, and in particular to a lost foam casting structure for casting large-diameter cast iron pipes. Background Technology

[0002] Currently, many large drainage pipes are made of large-diameter cast iron pipes, typically ranging from 80cm to 200cm in diameter. Due to their large diameter, these pipes are mostly produced using casting methods, with many employing lost foam casting molds. Lost foam casting molds are produced by extruding foamed clinker to create a prototype of the round pipe. This prototype is then pre-embedded in a casting sand box before casting. However, in actual use, because the lost foam is relatively thin and has a large diameter, it is easily deformed, especially the middle section of the side wall of the round pipe lost foam. This results in surface deformation of the cast iron product, leading to product defects. Therefore, this new lost foam structure is proposed. Utility Model Content

[0003] The purpose of this utility model is to address the above-mentioned situation by providing a lost foam casting structure for large-diameter cast iron pipes. This lost foam casting structure adopts a new design method, which effectively ensures the integrity of the lost foam during use and improves the quality of the cast products.

[0004] The specific solution of this utility model is: a lost foam casting structure for large-diameter cast iron pipes, which has a circular lost foam casting mold, and a support frame is provided inside the circular lost foam casting mold. The support frame has a central ring, and two layers of support rod groups extend radially outward from the outer wall of the central ring. Both the upper and lower support rod groups are composed of several support rods. One end of each support rod is connected to the outer wall of the central ring, and the other end of the support rod is connected to the inner wall of the circular lost foam casting mold.

[0005] Furthermore, each of the support rods described in this invention is made of glass fiber rod.

[0006] Furthermore, in this invention, several V-shaped diagonal braces are provided between the upper support rod group and the lower support rod group. The V-shaped apex of the V-shaped diagonal braces is connected to the outer wall of the central ring, and the other two ends of the V-shaped diagonal braces are connected to the inner wall of the circular tube lost foam casting. All V-shaped diagonal braces are radially distributed with the central ring as the center.

[0007] Furthermore, the V-shaped diagonal brace described in this utility model is made of glass fiber rod.

[0008] Furthermore, in this utility model, the support rods in the upper support rod group and the lower support rod group are arranged in a one-to-one correspondence, and the support rods in each layer are evenly spaced.

[0009] Furthermore, the central ring in this invention is also made of glass fiber material, and the height of the central ring is less than the axial length of the lost foam casting of the circular tube.

[0010] This utility model has the following beneficial effects:

[0011] 1. This utility model, by setting a supporting skeleton inside the lost foam casting of round tubes, effectively ensures that the lost foam does not collapse or deform during use, thus guaranteeing the casting quality of the round tube castings.

[0012] 2. This utility model also provides several V-shaped diagonal braces between the upper support rod group and the lower support rod group. The design of the V-shaped diagonal braces better supports the middle position of the round tube lost foam, so that the weak part located in the middle of the lost foam can also be effectively supported and strengthened, and the compressive strength of the lost foam is stronger. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the structure from the main view direction of this utility model;

[0014] Figure 2 This is a top view structural diagram of this utility model;

[0015] Figure 3 This is a schematic diagram of the supporting skeleton structure in this utility model.

[0016] In the diagram: 1—circular tube lost foam casting, 2—support rod, 3—center ring, 4—upper support rod assembly, 5—V-shaped diagonal brace, 6—lower support rod assembly. Detailed Implementation

[0017] The technical solution of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model. In the description of this utility model, it should be noted that the terms "upper," "lower," "inner," "outer," etc., indicating orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the utility model product is in use. They are only for the convenience of describing this utility model or simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed or operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0018] In the description of this utility model, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," and "connect" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0019] See Figures 1-3 This utility model discloses a lost foam casting structure for large-diameter cast iron pipes, comprising a circular lost foam casting 1, within which a supporting skeleton is provided. The supporting skeleton has a central ring 3. Furthermore, in this utility model, the central ring is also made of glass fiber material, and the height of the central ring is less than the axial length of the circular lost foam casting 1. Two layers of support rods extend radially outward from the outer wall of the central ring. Both the upper support rod group 4 and the lower support rod group 6 are composed of several support rods 2. One end of each support rod is connected to the outer wall of the central ring, and the other end is connected to the inner wall of the circular lost foam casting 1. Furthermore, in this utility model, the support rods in the upper and lower support rod groups are arranged in a one-to-one correspondence, and the support rods in each layer are evenly spaced.

[0020] Furthermore, each of the support rods described in this invention is made of glass fiber rod.

[0021] Furthermore, in this invention, a plurality of V-shaped diagonal braces 5 are provided between the upper support rod assembly and the lower support rod assembly. The V-shaped apex of each V-shaped diagonal brace is connected to the outer wall of the central ring, and the other two ends of each V-shaped diagonal brace are connected to the inner wall of the circular tube lost foam casting. All V-shaped diagonal braces are radially distributed around the central ring. Furthermore, the V-shaped diagonal braces in this invention are made of fiberglass rods.

[0022] This utility model is a lost foam mold. When in use, it is pre-embedded in the molding sand of the casting sand box. During the pre-embedding, the support frame is also pre-embedded in the molding sand. Due to the support of the upper support rod group, the lower support rod group and the V-shaped diagonal brace in the support frame, the lost foam mold can be well guaranteed to maintain its original shape.

[0023] The upper and lower support rod assemblies, as well as the V-shaped diagonal braces in this invention, are all made of glass fiber. Glass fiber has a softening point of 500-750℃ and a boiling point of 1000℃. When it comes into contact with molten iron (typically 1200-1400℃), it slowly vaporizes, and the residue can be removed through subsequent cleaning. Its vaporization process does not produce harmful gases, and its vaporization rate is lower than that of foam models, ensuring that the support continues until the metal begins to solidify.

[0024] This invention, by incorporating a support frame within the lost foam casting mold for circular tubes, effectively ensures that the lost foam does not collapse or deform during use, thus guaranteeing the casting quality of the circular tube castings. Furthermore, this invention includes several V-shaped diagonal braces between the upper and lower support rod assemblies. The V-shaped diagonal braces provide better support for the central area of ​​the lost foam, effectively reinforcing even the vulnerable parts in the middle of the mold and enhancing its compressive strength.

Claims

1. A large-diameter cast-iron pipe casting lost foam structure having a round pipe lost foam, characterized by: The lost foam casting of the circular tube is provided with a support frame. The support frame has a central ring. Two layers of support rods extend radially outward from the outer wall of the central ring. Both the upper and lower support rods are composed of several support rods. One end of each support rod is connected to the outer wall of the central ring, and the other end of the support rod is connected to the inner wall of the lost foam casting of the circular tube.

2. The lost foam casting structure for large-diameter cast iron pipes according to claim 1, characterized in that: Each of the aforementioned support rods is made of fiberglass rods.

3. The large-diameter cast-iron pipe casting lost foam structure according to claim 1, characterized in that: Several V-shaped diagonal braces are provided between the upper support rod group and the lower support rod group. The V-shaped apex of the V-shaped diagonal brace is connected to the outer wall of the central ring, and the other two ends of the V-shaped diagonal brace are connected to the inner wall of the circular tube lost foam casting. All V-shaped diagonal braces are distributed radially with the central ring as the center.

4. The large-diameter cast-iron pipe casting lost foam structure according to claim 3, characterized in that: The V-shaped diagonal brace is made of fiberglass rod.

5. The large-diameter cast-iron pipe casting lost foam structure according to claim 1, characterized in that: The support rods in the upper and lower support rod groups are arranged in a one-to-one correspondence, and the support rods in each layer are evenly spaced.

6. The large-diameter cast-iron pipe casting lost foam structure according to claim 1, characterized in that: The central ring is also made of fiberglass, and its height is less than the axial length of the lost foam casting of the circular tube.

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