JPH01241353A - Apparatus for casting metal block - Google Patents

Abstract

PURPOSE:To prevent the development of void or shrinkage hole in a cast metal block by arranging heat insulating means in molten metal introducing passage communicating with a cavity in a mold. CONSTITUTION:The spherical cavity 2 is arranged in the mold 1 and tip part 3a of the molten metal introducing cylinder 3 (introducing passage) fitted on the mold 1 is communicated with the cavity 2 through a pouring hole 4 in the mold 1. In inner circumferential face of this molten metal introducing cylinder 3, the heat insulating material 7 is fitted and the temp. of poured molten metal 5 is held to constant and the fluidity thereof is kept to good. Then, as the heat insulating material 7, such material that Portland cement is added as binder to asbestos fiber and pressurized to form and the like, is used. By this method, the development of void or shrinkage hole in the cast metal block can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION Object of the Invention (Field of Industrial Application) The present invention relates to a casting apparatus for producing metal ingots, particularly spherical ingots of aluminum or the like.

(Prior Art) Conventionally, in this type of casting apparatus, a molten metal introduction cylinder 3 is attached to a mold 1 having a spherical cavity 2, as shown schematically in FIG. 3 is in communication with cavity 2. The molten metal 5 injected from the introduction tube 3 is filled into the cavity 2, cooled from the outer periphery in contact with the mold 1, and solidified.

(Problem to be Solved by the Invention) In this way, in the conventional casting apparatus, solidification starts from the outer periphery in contact with the mold 1, and the inside of the metal ingot gradually becomes solid, so that The molten metal 5 also solidifies immediately, and solidification shrinkage occurs inside the metal lump with the entire outer periphery of the metal lump solidified and closed. Therefore, a cavity near a vacuum is created inside the metal block, and this vacuum pulls the parts of the outer periphery of the metal block where solidification is delayed and the parts of the mold that have poor heat absorption, causing pickets on the surface of the metal block. Occur.

The present invention improves the heat retention of the molten metal introduction path.
The purpose is to make it difficult for cavities and sink marks to form in metal lumps.

Structure of the Invention (Means for Solving the Problems) The present invention provides a heat retaining means in a molten metal introduction path communicating with a cavity in a mold.

(effect) Molten metal fills the gap through the inlet.

The heat retention of the molten metal passing through the introduction path is improved, cooling and solidification are delayed, and fluidity is improved.

(Example) First, the first embodiment embodies the present invention into a casting device for a spherical metal ingot.
An embodiment will be described with reference to FIG.

A spherical cavity 2 is provided in the mold 1, and a molten metal introduction tube 3 (introduction path) mounted on the mold 1 has a spherical cavity 2 formed at the end thereof.
a is communicated with this cavity 2 through an injection port 4 of the mold 1. The molten metal 5 injected from the introduction tube 3 passes through the injection port 4 and is filled into the cavity 2.

In particular, a heat insulating material 7 is fitted onto the inner peripheral surface of the molten metal introducing tube 3. In this embodiment, as the heat insulating material 7, a material obtained by press-forming asbestos fibers with Portland cement added as a binding material, or a calcium silicate plate is used.

Now, the molten metal 5 passes through the introduction tube 3 and is injected into the cavity 2 and the introduction@3. At this time, cavity 2
The molten metal 5 inside the mold 1 is cooled and solidified from the outer periphery that contacts the mold 1, and a vacuum cavity is created almost in the center due to solidification contraction. Since the metal 7 retains heat and maintains good fluidity, the molten metal 5 in the introduction tube 3, which maintains good fluidity, enters the internal vacuum cavity generated by solidification contraction of the metal lump described above.
is drawn in to prevent internal cavities and surface sink marks.

The second embodiment shown in FIG. 2 is a modification of the structure of the molten metal introduction tube 3 in the first embodiment, and the tip 7a of the heat insulating material 7 fitted into the introduction tube 3 is connected to the injection port 4. It is inserted through and protrudes into the inside of the cavity 2. This protruding tip 7a more actively keeps the area immediately below the introduction tube 3 warm from the cooling and solidification proceeding from the outer periphery of the metal lump. Similarly, the fluidity of the molten metal 5 inside the introduction tube 3 and immediately below it is ensured, making it difficult to form cavities and sink marks.

The third embodiment shown in FIG. 3 is also different from the first embodiment in that the structure of the molten metal introduction tube 3 is changed, and a heater 8 is fitted inside the introduction tube 3.

In this third embodiment as well, the function of the heater 8 increases the heat retention of the molten metal m5 inside the introduction tube 3 and directly below it, so that cavities and sink marks are less likely to form, as in the case of the first embodiment. .

The fourth embodiment shown in FIG. 4 is an application of the invention disclosed in Japanese Patent Publication No. 12389/1989, which was previously filed by the present applicant, to the present invention. As shown in Figure 4(a'), the first
．． 2.3 Molten metal 5 is injected into the cavity 2 and the introduction tube 3A through the introduction tube 3A, which is thinner than the introduction tube 3 used in Example. The molten metal 5 is cooled and solidified from the outer periphery in contact with the mold 1, and the molten metal 5 in the introduction tube 3A also solidifies relatively quickly compared to the 1.2.3 embodiments. Therefore, as shown in FIG. 4(b), a solidification shrinkage hole 10 is formed that expands within the cavity 2. Next, as shown in FIG. 4(C), when the sprue 9 is pressed by the rod 11, the inlet tube 3A breaks from the part 9a directly below where solidification has been delayed due to the heat retention effect shown in FIG. 4(b). Then, the sprue 9 is press-fitted into the solidification shrinkage hole 10. When the solidified molten metal 5 is taken out, as shown in FIG. 4(d), a substantially perfect spherical metal lump 12 with solidification shrinkage holes 10 filled with the sprue 9 is obtained. In this fourth embodiment, if the portion 9a directly below the introduction tube 3A solidifies too rapidly, the portion 9a directly below the introduction tube 3A
Although it becomes difficult to break the portion 9a, the heat insulating effect of the heat insulating member 7 delays cooling and solidification, making it easier to break the portion 9a immediately below.

Effects of the Invention According to the present invention, the heat retention means is provided in the introduction path for introducing molten metal into the cavity of the mold, so the heat retention of the molten metal is enhanced, the cold 2JI solidification of the molten metal is delayed, and the molten metal is Fluidity is improved and cavities and sink marks are less likely to form.

[Brief explanation of the drawing]

FIG. 1 is a schematic sectional view showing a first embodiment of the present invention, FIG. 2 is a schematic n-side view showing the second embodiment, FIG. 3 is a schematic sectional view showing the third embodiment, and FIG. Figures (a) (b) (c)
)(d) is a schematic sectional view showing the fourth embodiment, and FIG. 5 is a schematic sectional view showing the conventional example. 1... Mold, 2... Cavity, 3... Molten metal tube (introduction path), 4... Inlet (introduction path), 5...
- Molten metal, 7...insulating material (heat retention means), 8... heater (heat retention means). Patent applicant Tokai Rika Denki Seisakusho Co., Ltd. Agent Patent attorney On 1) Hironobu Figure 4 (a) Figure 4 (b) Figure 5

Claims (1)

[Claims] 1. A metal ingot casting apparatus characterized in that a heat retaining means (7, 8) is provided in a molten metal introduction path (3, 4) communicating with a cavity (2) in a mold (1).