Mold with cooling structure

Abstract

To provide a mold having a cooling structure that prevents the occurrence of voids from appearing on the final processed surface and enables the voids to be confined within a basin or a casting in the casting of non-ferrous metals. [Solution] A non-ferrous metal casting mold has a cooling pipe 3 for cooling molten metal 1, and a portion of the 360-degree cooling pipe is blocked to form a one-way cooling pipe with a cooling water inlet on one side and a drain outlet on the other side.

Description

[Technical Field]

[0001] The present invention relates to a non-ferrous metal forming die. This invention relates to a mold technology with a cooling structure that prevents the occurrence of porosity in non-ferrous metal casting from appearing on the final processed surface and makes it possible to confine porosity within the basin or casting. [Background technology]

[0002] When casting non-ferrous metals such as pistons, there is a problem with voids in the castings around convex or rod-shaped dies, such as the convex die in Figure 1 or the rod-shaped die in Figure 2. The cause is an inability to control the cooling of the die during casting. In the process of solidifying the molten metal (▲1▼) in the dotted line in Figure 1, it is important to cool it quickly starting from the vicinity of the die surface. Traditionally, a water-spray type cooling method has been used, as in Figure 1 and Figure 2 (▲2▼) old convex die. However, in order to prevent blowholes, the surface of the convex part is cooled as quickly as possible, but trying to cool it close to the surface can lead to damage to the mold, and the calcium carbonate contained in tap water can clog the holes, making it impossible to achieve a sufficient cooling effect.While it is difficult to solve the problems of damage and clogging and to completely eliminate blowholes, this technology moves blowholes away from the processed surface by sufficiently cooling the tip, reducing the number of blowholes on the processed surface and sealing them in without affecting product quality. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-072733 A structure for cooling the mold surface in one direction using a round bar mold. Depending on the mold shape, it was not possible to install an effective cooling pipe in one direction on the mold surface using conventional cutting processes. Summary of the Invention [Problem to be solved by the invention]

[0004] The conventional cooling method, as shown in Figure 1 and Figure 2 (2) in the old convex mold, involves spraying water onto the high-temperature mold surface to cool it, but there were issues with the cooling effect on the convex part of the mold that comes into contact with molten aluminum at over 700°C.When it is open to the atmosphere, the water vapor that evaporates immediately gets in the way and is repelled by the cooling pipe walls, making stable cooling impossible.In addition, when using city water as cooling water, there was the issue of clogging with calcium carbonate.

[0005] Conventional die manufacturing uses cutting, which can be done with an NC lathe or machining center, but it is difficult to cut the cooling pipes (3) shown in Figure 1 and Figure 2. Welding assembly is possible with cutting, but welding does not provide the required precision, and the strength of the welded surface is unstable. This invention is a technology that uses a metal 3D printer to create a three-dimensional cooling pipe structure as a processing method to realize a one-way cooling water structure at the convex part in Figure 1 or the tip of the round bar mold in Figure 2. [Effects of the Invention]

[0006] The mold cooling structure of this invention makes it possible to control the location of blowholes to a certain extent. Blobs are cavities created when the slow-cooling molten metal is pulled by contraction from the first solidified part. It is important to cool areas where blowholes are undesirable, so the entire mold surface is cooled before other areas. By using these cooling pipes to confine blowholes to convenient locations, blowhole defects can be suppressed. [Brief explanation of the drawings]

[0007] [Figure 1] An example of this invention is shown below. (1) A mold with one-way (3) cooling pipes and (4) drain valves arranged in a convex mold that constitutes a mold that surrounds the molten metal. Below that is a mold with a conventional cooling structure. [Figure 2] A modified example of a rod-shaped mold. ▲1▼ A mold with one-way (branch-collect type) ▲3▼ cooling pipes and ▲4▼ drain valves arranged in one rod-shaped mold that constitutes the mold surrounding the molten metal. Below that is a mold with a conventional cooling structure. DETAILED DESCRIPTION OF THE INVENTION

[0008] FIG. 1 is a cross-sectional view of a mold according to an embodiment of the present invention. As shown in this figure, the structure is one in which a tube-type cooling pipe, which cannot be obtained by cutting, is formed using a 3D printer on a cylindrical convex mold. ~Composition and Effects~ By cooling more evenly and closer to the mold surface than with conventional molds, the molten metal solidifies from near the mold surface, which allows for voids to be pushed further in. The final product that is machined after casting is cut off by about 1 mm, but the absence of voids near the machined surface reduces defects. Compared to conventional cooling, cooling control is more reliable and the cooling rate is faster. ~Specific examples and variations~ Figure 2 shows a modified rod-shaped mold. When it is difficult to install a complete one-way cooling pipe due to its thinness, this is a cooling pipe that branches from the inlet and converges into a drain. [Explanation of symbols]

[0009] ▲1▼Molten metal Molten metal to be poured into the mold (aluminum, brass, copper, etc.) ▲2▼ Conventional molds and their cooling methods ▲3▼One-way cooling pipe formed by 3D modeling ▲4▼ Valve that controls the cooling water flow rate (cooling rate)

Claims

1. A mold for casting non-ferrous metals as shown in Figure 1, which has a one-way cooling pipe (3) as shown in the A-A cross section.A rod-shaped mold as shown in the B-B cross section of Figure 2, which has a one-way cooling pipe inside that branches in two directions and drains water.

2. The cooling structure (4) has a drain valve that has the function of supplying and draining the cooling pipe of the mold and can control the cooling effect.

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