JPH06114536A - Method for casting metallic mold - Google Patents

Abstract

PURPOSE:To reduce the material cost and shorten a lead time of a metallic mold manufacture by reducing the amount of alloy (molten metal) in the casting metallic mold. CONSTITUTION:After arranging plural ceramic spacers 7 in a mold 6, the alloy 9 in the molten state that is separately prepared is poured and casted by regulating the float-up of each ceramic spacer 7 to a specified height by a wire net 8. By casting the ceramic spacer 7 to the position being apart from the metallic mold surface in the lower surface, the amount of the alloy can effectively be reduced without impairing the function of the casting metallic mold.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a die casting method.

[0002]

2. Description of the Related Art Conventionally, for example, of press dies, a simple die for a relatively small number of presses is cast from a zinc alloy or the like.

[0003]

The alloys used for the above conventional casting molds are generally expensive, and the larger the mold, the more the material cost accounts for and the longer the solidification time of the molten metal. It has a great influence on the lead time of mold making.

Therefore, the present invention reduces the amount of metal in the mold,
It is a technical issue to be solved to reduce the material cost and shorten the lead time of die manufacturing.

[0005]

[Means for Solving the Problems] For this purpose, the following die casting method was created. That is, after arranging a predetermined number of ceramic spacers that float with respect to the molten metal in the mold, the molten metal is poured into the mold, and the ceramic spacers are cast at a position separated from the surface to be the mold surface. I am trying.

[0006]

In the above-described mold casting method, the ceramic spacers placed in the mold are floated by the buoyancy during pouring, and are cast at a position separated from the mold surface.
Therefore, since the mold surface is made of cast metal, the function and strength are not impaired. In addition, the amount of metal (molten metal) corresponding to the amount of ceramic spacers is reduced.

[0007]

EXAMPLES As one example of the present invention, a method for molding a press die (convex die) by sand casting will be described below with reference to FIGS. First, as shown in FIG.
After the model 2 and the flask 3 are installed in the above, the sand 4 is put and compacted. After that, as shown in FIG. 2, the die blank 3 is inverted and set on the table 5. Next, as shown in FIG. 3, a large number of spherical ceramic spacers 7 are placed in the mold 6.
(Specific gravity of about 3.5) are arranged side by side and are arranged so that a sufficient space is left above the ceramic spacer 7.

Next, as shown in FIG. 4, an alloy 9 (a zinc alloy in this embodiment, a specific gravity of about 8.5) 9 is fixed by fixing a wire net 8 covering the entire upper surface of the casting mold 3 and is melted. Add pouring water. Then, the ceramic spacer 7 receives the buoyancy and contacts the metal net 8, and the gap between the ceramic spacers 7 is filled with the molten metal, so that the ceramic spacer 7 and the alloy 9 are mixed in the upper portion of the mold 6. Then, as shown in FIG. 5, after the alloy 9 is solidified, the ceramic spacer 7 is cast into the mold 10 that has been demolded at a position (the lower side in the drawing) separated from the mold surface 11 on the upper surface thereof. ing. In addition,
The used wire netting 8 is removed from the cast mold 10 which has been demolded by appropriate means.

Next, as another example, a method of molding a press die (concave die) by model direct casting will be described with reference to FIGS. 6 to 9. As shown in FIG. 6, while covering the model 13 installed on the metal frame 12 with the silicone rubber sheet 14,
Air is sucked from the back surface (lower side in the drawing) of the model 13 by a vacuum pump (not shown), and the silicone rubber sheet 14 is brought into close contact with the model 13 to form a lower mold. Thereafter, as shown in FIG. 7, a casting frame 15 is installed on the metal frame 12 to form a mold 16, a number of ceramic spacers 7 are arranged on the silicon rubber sheet 14, and a space is provided above the ceramic spacers 7. Arrange so that it remains enough. Next, as shown in FIG. 8, when the separately melted alloy 9 is poured into the mold 16 from the pouring port of the casting frame 15, the ceramic spacer 7 receives the buoyancy and contacts the inner surface of the casting frame 15, The ceramic spacer 7 and the alloy 9 are in a mixed state. Then, as shown in FIG. 9, after the alloy 9 is solidified, the ceramic spacer 7 is cast into the demolding die 17 at a position (lower side in the figure) separated from the die surface 18 on the upper surface thereof. ing.

In any of the die casting methods described above, the ceramic spacer 7 is lifted by the difference in specific gravity between the molten alloy 9 and the ceramic spacer 7, and the lift is restricted to a predetermined height. 7 is mixed with alloy 9 and cast. Therefore, the amount of the alloy 9 (molten metal) can be reduced without changing the shape of the back surface of the casting molds 10 and 17 from the conventional one, and the weight of the molds can be reduced. And casting mold 1
Since the amount of 0, 17 alloy is reduced and the wall thickness is optimized, the casting surface is cooled rapidly, the solidification shrinkage amount is reduced, and the dimensional accuracy of the casting surface is improved. Nest formation is prevented. Also, the amount of heat required for melting the alloy is reduced, which contributes to energy saving. Moreover, since the above-mentioned casting molds 10 and 17 have the ceramic spacers 7 cast into the back surface of the mold, they have sufficient compressive strength and do not impair the function as a press mold.

[0011]

As described above, according to the die casting method of the present invention, the amount of metal (molten metal) can be effectively reduced, resulting in reduction of material cost and lead time of die production. There is an effect that it can be shortened.

[Brief description of drawings]

FIG. 1 is a cross-sectional view for explaining a manufacturing process by sand casting of a casting mold according to an embodiment, showing a state in which casting sand is filled.

FIG. 2 is a cross-sectional view for explaining a manufacturing process of the casting mold of the embodiment by sand mold casting, showing a state where the mold is cut out.

FIG. 3 is a cross-sectional view for explaining a manufacturing process by sand casting of a casting mold of an example, showing a state where ceramic spacers are placed in the mold.

FIG. 4 is a cross-sectional view for explaining a manufacturing process by sand casting of the casting mold of the example, showing a state in which molten metal is poured into the mold.

FIG. 5 is a cross-sectional view of a casting mold (convex mold) of an example, showing a state where the mold is released.

FIG. 6 is a cross-sectional view for explaining a manufacturing process of another example of a casting mold by model direct casting, showing a state in which a model on a metal frame is covered with a silicon sheet.

FIG. 7 is a cross-sectional view for explaining a manufacturing process of another example of a casting mold by model direct casting, showing a state where ceramic spacers are placed in a mold.

FIG. 8 is a cross-sectional view for explaining a manufacturing process of another example of a casting mold by model direct casting, showing a state in which molten metal is poured into the mold.

FIG. 9 is a cross-sectional view of a casting mold (concave mold) of another example, showing a state where the mold is released.

[Explanation of symbols]

 2 Model 6,16 Mold 7 Ceramic spacer 9 Alloy (molten metal) 10,17 Casting mold (mold) 11,18 Mold surface

Front page continuation (72) Inventor Tatsuya Nagata 5-14 Midorigaoka, Toyota-shi, Aichi Otoyo Seiki Co., Ltd.

Claims (1)

[Claims] 1. After arranging a predetermined number of ceramic spacers that float with respect to the molten metal in the mold, the molten metal is poured into the mold, and the ceramic spacers are cast at a position separated from the mold surface. A method of casting a die, which is characterized in that