JPS613647A - Mold device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an apparatus for feeding molten metal from an airtight chamber into a mold from the bottom thereof by means of a pressure difference, thereby casting a cast product with excellent physical and mechanical properties.

Conventionally, a device (U.S. Pat. No. 2.8
39.801) is known.

Such equipment includes a mold forming a mold cavity and a sprue system having a gas-impermeable runner. A seat surface is formed at the lower end of this runner, and a removable plug is provided on this seat surface, and by removing this plug, the molten metal in the runner can be discharged. It is configured. Additionally, this gas-impermeable runner is connected to a fixed hot water pipe placed in an airtight chamber that supplies the molten metal, and the gap between the lower part of this runner and the above-mentioned fixed hot water pipe is gas permeable. and connected via a molten metal impermeable seal.

However, such a device requires a mechanism to drive the plug provided in the gas-impermeable runner, and the drive mechanism for such a plug is required to drive the molten metal in the sprue system or mold cavity. However, when this molten metal solidifies, it becomes extremely troublesome to remove the plug and the like.

In addition, such molding equipment must be provided with a seal connecting the gas-impermeable runner to the heating pipe in the airtight chamber, which seal must be provided during the supply of molten metal to the sprue system. Since it comes into direct contact with the molten metal, its lifespan is short, and the seal must be replaced after each casting.

The present invention has been made based on the above circumstances, and is a device for supplying molten metal from an airtight chamber into a mold from the lower part thereof by a pressure difference, in which a removable stopper or the like is provided in a gas-impermeable runner. It is an object of the present invention to provide a molding apparatus which can prevent the molten metal from directly contacting the seal connecting the runner and the supply pipe in the airtight chamber.

That is, the present invention provides a method that includes a mold forming a mold cavity and a sprue system for supplying molten metal, and supplies molten metal to the bottom of the mold from within an airtight chamber by differential pressure.
The sprue system has a gas-impermeable runner and a gas-permeable runner that connects the gas-impermeable runner to the mold cavity and has gas permeability when molten metal is supplied to the mold cavity. and an overflow supply layer that is impermeable to gas after hot water supply is completed.

In the above-mentioned overflow supply layer, a lining gap is formed between the mold and the spaced filler having the through hole.

This spacing filler is made of the same material as the mold material in the vicinity of the overflow supply layer.

Also, a seal is arranged outside the gas-impermeable runner to connect the mold and the supply pipe in the airtight chamber.

In the apparatus of the present invention configured in this manner, when the mold cavity is filled with molten metal, the molten metal in the sprue system is automatically overflowed and discharged through the gas-impermeable runner, No mechanical structural parts required. The pressure within this sprue system is then balanced with the liquid head pressure of the molten metal within the mold cavity at the overflow setting surface.

Further, the arrangement of the overflow supply layer of the present invention can be set at an appropriate position depending on the shape of the cast product, the lit solidification procedure, etc.

Furthermore, more than one overflow feed layer can also be provided.

Furthermore, since the sealing member does not come into contact with molten metal but only with gas, its lifespan is extended and reliability is also improved.

Therefore, according to the apparatus of the present invention, casting materials can be used effectively, work efficiency and reliability can be improved, and cast products with excellent physical and mechanical properties can be manufactured.

Embodiments of the present invention will be described below with reference to the drawings.

This figure shows a cross section of a molding device according to an embodiment of the present invention, with the part to the right of the center line showing one using a sand mold, and the part to the left of the center line showing one using a metal mold and a sand core. shows. This example has Bulgarian inventor certificate No. 3.
3.476.

The mold of this device is composed of a lower mold 1 and an upper mold 2 that form a mold cavity 3, and a sprue system that supplies molten metal. This sprue system comprises a gas-impermeable runner 4 formed in a pipe 41, which communicates with the mold cavity 3 via an overflow feed layer 6. ing.

This overflow supply layer 6 is gas permeable while the molten metal is being supplied into the mold cavity 3, and gas impermeable after the mold cavity 3 is filled with molten metal. It is structured to be sexual. That is, in this overflow supply weir 6, a lining gap 8 is formed between the upper die 2 and the spacing filler metal 7. The spacer filler 7 is made of the same material as the upper mold 2, and a plurality of through holes 71 are formed in the spacer filler 7.

Further, a sealing surface is formed on the outside of the gas-impermeable runner 4, and this sealing surface is along the radial direction in the case on the left side of the center line, and along the circumferential direction in the case on the right side of the center line. It is provided. The mold is connected to a movable supply pipe 11 by this sealing surface 5 and sealing member 12, and this movable supply pipe 11 is arranged in a space 101 within an airtight chamber 10 containing molten metal.

Further, this casting is configured to be performed in a reverse pressure, that is, in a vacuum, and the above mold is placed in a space 9 inside an airtight chamber 9.
It is located at 1.

Note that the overflow supply weir 6 portion of the upper die 2 may be configured to be gas impermeable, and the spacing filler metal 7 may be omitted.

Next, the operation of this embodiment will be explained.

First, after connecting the mold to the movable supply pipe 11 via the seal member 12, the gap between the space 101 and the mold gap 3 in the case of low-pressure casting method, or between the space 101 and the air gap 1II91 in the case of vacuum casting method. A pressure difference is applied between the two. This pressure difference causes molten metal to be supplied into the mold cavity Mfg,3. At the same time, the molten metal flows into the through hole 71 of the spaced filler metal 7.
Due to the small thickness of this lining cavity 8, this molten metal rapidly solidifies and forms a gas-impermeable layer.

When the mold cavity 3 is filled with molten metal and a gas-impermeable layer is formed within the lining cavity 8,
Space 1 formed between the pipe 41 and the movable supply pipe 11
11 is communicated with the air mro1 in the airtight chamber 10 to supply gas pressure. As a result, the molten metal in the sprue system flows down into the airtight chamber 10 and is recovered. When the liquid level in the overflow supply weir 6 falls to a set overflow liquid level as shown in the figure, the flow of the molten metal stops, and the liquid level of the molten metal is maintained at this level. In addition, the pressure in this case is set to a pressure that is balanced with the force such as the liquid head pressure of the molten metal in the mold cavity that acts on the overflow liquid level, and is set to a higher pressure if necessary. be done. After the molten metal is discharged from the sprue system, the pressure is maintained at a predetermined value, and when the molten metal in the mold cavity solidifies, the mold is removed and the cast product is completed. Then, the same procedure is repeated.

[Brief explanation of the drawing]

The figure is a sectional view of an embodiment of the invention. 1... Lower mold, 2... Upper mold, 3... Mold cavity, 4
... gas impermeable lit path, 6... SIi flow supply weir, 7... lining void, 10... airtight chamber, 1
1...Movable supply pipe.

Claims (5)

[Claims] (1) In a device comprising a mold forming a mold cavity and a sprue system for supplying molten metal, the molten metal is supplied to the bottom of the mold from within an airtight chamber by a pressure difference, and the sprue system is gas impermeable. This gas-impermeable runner 4 is connected to the mold cavity 3, and when molten metal is supplied to the mold cavity 3, it has gas permeability, and after the supply of the molten metal is finished. is a gas-impermeable overflow supply weir 6
A molding device characterized by comprising: (2) The mold apparatus according to claim 1, wherein the overflow supply weir 6 is provided with a lining gap 8 formed between the upper die 2 and the spacer filler 7. (3) The mold apparatus according to claim 2, wherein a through hole 71 is formed in the spacing filler metal 7. (4) The mold apparatus according to claim 2 or 3, wherein the spacer filler 7 is made of the same material as the upper mold 2. (5) A sealing surface 5 is provided on the outside of the gas-impermeable runner 4.
2. The molding apparatus according to claim 1, wherein the mold is connected to an airtight chamber for supplying molten metal by means of this sealing surface and the sealing member 12.