Long cartridge case-shaped shell

Abstract

The invention discloses a long cartridge case-shaped shell. A method of forming a metal tube with a closed end includes cutting a blank from a solid circular metal wire, forming an axial bore in the blank by backward extrusion to create a hollow sidewall having a thickness, and reducing the thickness of the sidewall by using one or more modified Hooke extrusion processes.

Description

Technical Field

[0001] This invention relates to a method for making slender hollow components from solid metal wire. Background Technology

[0002] U.S. Patents 10,495,430 and 11,333,473 disclose a method for manufacturing a long, cartridge-like shell, which involves multiple backward extrusions of an initial solid cylindrical blank. The forces involved can sometimes result in short tool life, thus necessitating a tubular forming process that applies less pressure to the tool. Summary of the Invention

[0003] This invention requires only a single backward extrusion, less severe than existing processes, to form hollow components suitable for manufacturing long cartridge-like shells. By using one or more modified continuous Hooker extrusions, additional backward extrusion is avoided, thereby achieving the desired wall thickness in the workpiece, which can be a preform of a long cartridge shell with a length exceeding 2.5 times its diameter.

[0004] The modified Hooke extrusion process differs from the traditional Hooke extrusion process. In the traditional Hooke extrusion process, the inner diameter of the part remains unchanged. However, in the modified Hooke extrusion process, the outer diameter of the part is maintained.

[0005] By reducing the total forming load and energy, tool life can be increased, and smaller, faster cold forming machines can be used. Attached Figure Description

[0006] Figure 1 The molding steps used in this invention are shown;

[0007] Figure 2 The beginning of the modified Hooker extrusion process is shown;

[0008] Figure 3 The completed modified Hooke extrusion process is shown. Detailed Implementation

[0009] Figure 1 The forming steps shown are typically performed on a multi-stage cold forming machine. The blank 10 is cut from a solid circular metal wire fed into the forming machine. On the first stage, the blank 10 is squared up at the edges. On the second stage, the blank 10 is backward extruded, reducing its internal diameter and thus decreasing the tooling load. The forming load required to produce a backward extrusion hole decreases as the area decreases. Here, the hole produced by backward extrusion is the smallest, whereas earlier processes require a larger hole to form the nozzle of the blank.

[0010] like Figure 1 As shown, the billet 10, which is extruded backward, undergoes a first modified Hooke extrusion on the next operating table, and a second modified Hooke extrusion on the subsequent operating table. Figure 2 This shows the beginning of the modified Hooke squeeze. Figure 3 The completed modified Hooke squeeze is shown. From Figure 2 and Figure 3 It can be seen that only the sidewalls of blank 10 are extruded, so the reduction in area is relatively small. Compared with the previous multiple backward extrusion process, the total forming load is estimated to be reduced by 50%, and energy consumption by 40%. The part can be finally stretched to the final sidewall thickness on the same forming machine because the previous forming steps have been completed.

[0011] It is obvious that the invention has been disclosed by way of example, and various changes can be made by adding, modifying, or deleting details without departing from the reasonable scope of the teachings contained herein. Therefore, the invention is not limited to the specific details of this disclosure, unless the following claims necessarily define it as such.

Claims

1. A method for forming a metal tube with a closed end, comprising cutting a blank from a circular metal wire, extruding an axial hole in the blank to produce a hollow sidewall with a thickness, and reducing the thickness of the sidewall by using a modified Hooke extrusion process.

2. The method according to claim 1, characterized in that, In the modified Hooke extrusion process, the outer diameter of the sidewall is limited.

3. The method according to claim 1, characterized in that, Hooke's extrusion, which involves a series of modifications to the sidewalls.

4. The method according to claim 1, characterized in that, The forming part is drawn to the final sidewall thickness of the desired component.

5. The method according to claim 4, characterized in that, This method is performed on a single molding machine.

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