A centrifugal casting mould for a variable diameter bore

Abstract

The utility model discloses a centrifugal casting type cylinder of variable diameter inner hole, including type cylinder body, the both ends of type cylinder body are connected with sealing assembly, the inside pouring gate of type cylinder body is variable diameter through -hole, and its shape corresponds with the variable diameter pipe blank shape of required forming, variable diameter through -hole includes equal diameter section and variable diameter section. The utility model can improve the manufacturing efficiency of variable diameter pipe fitting greatly, reduce the consumption of cast molten steel, and significantly reduce the subsequent processing amount, and the effect is obvious in cost control aspect, and can improve the convenience of end sealing assembly installation.

Description

Technical Field

[0001] This utility model relates to the field of centrifugal casting technology, specifically to a centrifugal casting mold cylinder with a variable diameter structure that can achieve near-net-shape forming of variable diameter pipe fittings. Background Technology

[0002] Centrifugal casting is a casting method in which molten metal is poured into a high-speed rotating mold, and centrifugal force is used to fill the cavity and form a casting. This method does not require a core; the molten metal can uniformly fill the casting cylinder under centrifugal force, directly forming a cylindrical inner hole. It is especially suitable for the production of pipe and cylinder castings, and can produce castings with dense structure and excellent mechanical properties.

[0003] However, in actual production, the structure of the mold cylinder and its end sealing method have a significant impact on the casting quality and demolding efficiency. In existing technologies, the mold cylinder is usually of a constant diameter. When casting variable-diameter metal tube blanks, a mold cylinder matching the maximum diameter of the product must be selected for casting. However, this method results in high metal consumption, large casting allowance, and significant subsequent machining, leading to low production efficiency. Furthermore, the end caps at both ends of the mold cylinder need to be reliably fixed to withstand the enormous pressure generated by the molten metal during high-speed rotation, preventing leakage and ensuring production safety and casting quality. Existing technologies typically use tapered pins to press the end caps into place from inside the mold cylinder. This method requires hammering from the inside of the mold cylinder outwards. Although centrifugal force can be used to tighten the pins as they rotate at high speed, resulting in high locking reliability, it is inconvenient to install due to the limited space inside the mold cylinder. Utility Model Content

[0004] This utility model proposes a centrifugal casting mold cylinder with a variable diameter inner hole. Its purpose is to solve the problems of large subsequent processing volume, high metal consumption, and inconvenient installation of end pins when processing variable diameter pipe fittings using a constant diameter mold cylinder.

[0005] The technical solution of this utility model is as follows: A centrifugal casting mold cylinder with a variable diameter inner hole includes a mold cylinder body, with sealing components connected to both ends of the mold cylinder body. The internal gating channel of the mold cylinder body is a variable diameter through hole, the shape of which corresponds to the shape of the variable diameter tube blank to be formed. The variable diameter through hole includes a constant diameter section and a variable diameter section.

[0006] As a further improvement of this utility model, the constant diameter section includes a large diameter section and a small diameter section, and the large diameter section and the small diameter section are connected by a variable diameter section. The variable diameter section and the large diameter section and the small diameter section are all connected by rounded corners.

[0007] As a further improvement of this utility model, the left and right ends of the mold body are respectively provided with stepped holes coaxial with the gating. The stepped holes are connected to the sealing assembly by detachable fasteners. The sealing assembly includes an end cap disposed on the outer side and an asbestos gasket disposed in close contact with the inner side of the end cap.

[0008] As a further improvement of this utility model, the fastener is a tapered pin, and a radially extending pin hole is provided on the side wall of the stepped hole.

[0009] As a further improvement of this utility model, the end of the cylindrical body is provided with three pin holes evenly distributed in the circumference.

[0010] As a further improvement of this utility model, all the pin holes are through holes that penetrate the side wall of the cylindrical tube.

[0011] As a further improvement of this utility model, the pin hole is a tapered through hole that extends radially along the cylindrical body and is larger on the outside and smaller on the inside. The pin used has the same taper as the tapered through hole, and the outer side of the end cap is provided with a chamfer, the angle of which is consistent with the taper of the pin.

[0012] As a further improvement of this utility model, the large end of the pin is provided with a countersunk hole, and a bolt is connected in the countersunk hole, with the top of the bolt protruding from the top surface of the pin; the outer edge of the tapered through hole is provided with an annular boss with external threads, and a cap is threadedly connected to the boss, with gaps left between the cap and the outer wall of the cylinder body, as well as between the cap and the top surface of the boss.

[0013] Compared with the prior art, the present invention has the following advantages: (1) By using a centrifugal casting mold with a variable diameter inner hole, the variable diameter tube blank is directly cast in a near-net-shape manner, which can greatly reduce the amount of molten metal used and the amount of machining work after demolding, significantly reduce costs and greatly improve the processing efficiency of the variable diameter tube blank.

[0014] (2) In the embodiment where a tapered through hole is provided at the end of the mold cylinder, a pin with the same taper and a tapered through hole are used, and a bolt is provided at the large end of the pin to facilitate the removal of the pin during demolding. In addition, the pin is prevented from flying out when the mold cylinder rotates at high speed by a circular boss on the outer edge of the tapered through hole and a cap that is threaded to the boss. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the finished reducing pipe fitting structure; Figure 2 This is a schematic diagram of the variable diameter tube blank structure; Figure 3 This is a cross-sectional structural diagram of Embodiment 1 of the present utility model; Figure 4 This is a left view of Embodiment 1 of the present invention; Figure 5 This is a schematic diagram of the end section in Embodiment 2 of this utility model (this diagram is used to show the connection between the cylindrical body and the sealing assembly).

[0016] The reference numerals in the figures include: 1. Pin; 2. End cap; 3. Asbestos gasket; 4. Cylinder body; 5. Support roller; 6. Boss; 7. Cover; 8. Bolt; 9. Turned part. Detailed Implementation

[0017] The technical solution and effects of this utility model will be described in detail below with reference to specific embodiments and accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments.

[0018] like Figure 1 The image shows a finished product of a variable diameter metal tube. This utility model discloses a method for producing... Figure 2 The diagram shows a centrifugal casting mold for a variable-diameter inner bore of a variable-diameter metal tube blank. Example 1

[0019] A centrifugal casting mold cylinder with a variable-diameter inner bore includes a cylinder body 4, on which a limiting protrusion is provided for constraining it between two support rollers 5 of a centrifuge. The internal gating system of the cylinder body 4 is a variable-diameter through-hole, the shape of which corresponds to the shape of the variable-diameter metal billet to be formed. Considering the flow and solidification characteristics of molten metal under centrifugal force, the variable-diameter through-hole includes a constant-diameter section and a variable-diameter section. To avoid stress concentration, reduce crack formation, improve the filling performance of the molten metal in the variable-diameter region, and ensure the quality and dimensional accuracy of the billet's outer wall, a rounded transition is used between the variable-diameter section and the adjacent constant-diameter section. Figure 3 As shown, the variable diameter through hole in this embodiment includes a large diameter section on the left and a small diameter section on the right, with the variable diameter section between the large diameter section and the small diameter section. The tube blank cast using the molded tube described in this embodiment only needs to have the machined portion 9 corresponding to the variable diameter section removed, such as... Figure 2 As shown, finished pipe fittings that meet the requirements can be obtained with minimal processing.

[0020] The variable-diameter through-hole has stepped holes coaxial with the gating system at both ends. Seal components to prevent molten metal from flowing out are connected to these stepped holes via detachable fasteners. The seal components include an end cap 2 on the outer side and an asbestos gasket 3 tightly fitted inside the end cap 2. Both the end cap 2 and the asbestos gasket 3 are circular. To balance sealing and venting, both the end cap 2 and the asbestos gasket 3 have through holes, which helps to expel gas from the mold cavity during casting, reducing porosity defects and improving the density of the casting. Preferably, both the end cap 2 and the asbestos gasket 3 are annular structures.

[0021] Specifically, the fastener is a tapered pin 1, and radially extending pin holes are provided on the sidewall of the stepped hole. To ensure uniform force distribution on the end cap 2, avoid uneven loading or loosening due to single-point fixing, and ensure dynamic balance of the die cylinder under high-speed rotation, three circumferentially distributed pin holes are provided at the end of the die cylinder, such as... Figure 4 As shown.

[0022] In this embodiment, when installing the end cap 2, the tapered pin 1 is inserted into the pin hole from the inside of the cylindrical body 4, and then tapped to press the end cap 2 tightly. All the pin holes are through holes penetrating the side wall of the cylindrical body 4. During disassembly, a tool is inserted into the pin hole from the outside to push the pin 1 out, and the end cap 2 can then be removed. Example 2

[0023] The difference between this embodiment and Embodiment 1 lies in the fixing structure of the end cap 2.

[0024] like Figure 5 As shown, in this embodiment, the pin hole is a tapered through hole extending radially along the cylindrical body 4, with a larger outer diameter and a smaller inner diameter. The pin 1 used has the same taper as the tapered through hole. Correspondingly, a chamfer is provided on the outer side of the end cap 2, and the bevel angle of the chamfer is consistent with the taper of the pin 1. To facilitate disassembly, a countersunk hole is provided at the larger end of the pin 1, and a bolt 8 is connected in the countersunk hole, with the top of the bolt 8 protruding from the top surface of the pin 1.

[0025] Furthermore, to ensure operational safety, an annular boss 6 with external threads is provided on the outer edge of the tapered through hole, and a cover 7 is threaded onto the boss 6. After the cover 7 is installed, gaps are left between it and the outer wall of the mold body 4, and between it and the top surface of the boss 6. The reserved gaps provide compensation space for thermal expansion, which can avoid structural interference or excessive stress caused by temperature changes, thereby ensuring the long-term safe operation of the mold body 4 under high temperature and high speed conditions. The cover 7, as a secondary safety device, can prevent the pin 1 from flying out during the high-speed rotation of the mold body and causing a safety accident.

[0026] In this embodiment, pin 1 is driven through the cylinder wall from the outside to press the end cap 2. For disassembly, simply unscrew the cap 7 to remove pin 1. This external installation method optimizes the operation process. It ensures connection strength while balancing ease of installation and disassembly with operational safety.

[0027] It should be noted that, as will be apparent to those skilled in the art, this utility model is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or essential characteristics of this utility model. The scope of this utility model is defined by the claims rather than the foregoing description.

Claims

1. A centrifugal casting mold cylinder with a variable diameter inner bore, comprising a mold cylinder body (4), wherein sealing assemblies are connected to both ends of the mold cylinder body (4), characterized in that: The internal gating channel of the cylindrical body (4) is a variable diameter through hole, the shape of which corresponds to the shape of the variable diameter tube blank to be formed. The variable diameter through hole includes a constant diameter section and a variable diameter section.

2. The centrifugal casting mold cylinder with variable diameter inner bore as described in claim 1, characterized in that: The equal diameter section includes a large diameter section and a small diameter section. The section between the large diameter section and the small diameter section is a variable diameter section. The variable diameter section and the large diameter section and the small diameter section are all connected by rounded corners.

3. The centrifugal casting mold cylinder with variable diameter inner bore as described in claim 1, characterized in that: The left and right ends of the cylindrical body (4) are respectively provided with stepped holes coaxial with the gating channel. The stepped holes are connected to the sealing assembly by detachable fasteners. The sealing assembly includes an end cap (2) set on the outside and an asbestos gasket (3) set close to the inside of the end cap (2).

4. The centrifugal casting mold cylinder with variable diameter inner bore as described in claim 3, characterized in that: The fastener is a tapered pin (1), and a radially extending pin hole is provided on the side wall of the stepped hole.

5. The centrifugal casting mold cylinder with variable diameter inner bore as described in claim 3, characterized in that: The end of the cylindrical body (4) is provided with three pin holes evenly distributed in the circumference.

6. The centrifugal casting mold cylinder with variable diameter inner bore as described in claim 5, characterized in that: All the pin holes are through holes that penetrate the side wall of the cylindrical section.

7. The centrifugal casting mold cylinder with variable diameter inner bore as described in claim 5, characterized in that: The pin hole is a tapered through hole that extends radially along the cylindrical body (4) and is larger on the outside and smaller on the inside. The pin (1) used has the same taper as the tapered through hole. The end cap (2) has a chamfer on the outside, and the chamfer angle is consistent with the taper of the pin (1).

8. The centrifugal casting mold cylinder with variable diameter inner bore as described in claim 7, characterized in that: The large end of the pin (1) is provided with a countersunk hole, and a bolt (8) is connected in the countersunk hole. The top of the bolt (8) protrudes from the top surface of the pin (1). The outer edge of the tapered through hole is provided with an annular boss (6) with external threads. A cap (7) is threaded on the boss (6). There are gaps between the cap (7) and the outer wall of the cylindrical body (4) and between the cap (7) and the top surface of the boss (6).

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