JPH0315249Y2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a low-pressure casting apparatus for molten metal such as aluminum.

<Prior art> When casting molten metal such as aluminum, a ceramic stalk with excellent heat resistance is inserted from above in place of a metal stalk into the molten metal housed in a closed holding furnace, and a ceramic stalk with excellent heat resistance is inserted through the stalk. A low-pressure casting device is used that presses and casts molten metal into a mold provided in the upper part of a holding furnace using high-pressure air acting on the surface of the molten metal.

In the above device, the upper mold and the ceramic
In order to prevent the load from the metal intermediate stalk inserted between the stalk and the upper mold from directly applying to the ceramic stalk, an upper part is placed between the flange of intermediate stalk 0 and the upper surface of the flange of ceramic stalk 3, as shown in Figure 2. Insert the bracket 7, install the lower bracket 5 that fits into the stepped part of the lid 1 and supports the lower surface of the ceramic flange, insert the packing between the flange surface of the ceramic stalk and each of the brackets above, and replace the upper and lower brackets. The structure is such that it tightens and maintains airtightness.

<Problems to be solved by the invention> However, in the above device, an impact load of about 5 tons is intermittently applied to the upper bracket via the intermediate stalk, and if the intermediate stalk is deformed by the mold load, The inner circumferential edge of the lower end of the deformed intermediate stalk presses the upper bracket and crushes the packing, applying an impact or bending load to the ceramic stalk flange, which tends to cause damage such as cracking of the ceramic stalk.

Considering that the damage to the ceramic stalk is due to the mechanical impact load and bending stress applied to it, the inventors have developed various structures that can absorb this mechanical impact load and do not apply bending stress to the ceramic stalk. After further consideration, we completed the present invention.

<Means for solving the problem> The low-pressure casting device using a ceramic stalk according to the present invention supplies molten metal in a holding furnace sealed by a lid to the mold above the lid through the ceramic stalk and the intermediate stalk. In the casting apparatus, the molten metal is press-fitted into the mold and cast by air pressure acting on the surface of the molten metal, in which a flange is formed near the upper end of the ceramic stalk, and the lower surface of the flange is connected to the molten metal. an upper support supported by a stepped portion of a lower support fitting set on a seat of the lid, a sealing material being inserted between the outer periphery of the flange and an inner wall of the lower receiving fitting, and the sealing material being coupled to the lower support fitting; The intermediate stalk is pressed by a metal fitting, and the intermediate stalk is supported by the upper receiving metal fitting, so that a required distance is maintained between the stalk and the end face of the ceramic stalk.

An example of the present invention will be described based on the drawings.
FIG. 1 is a longitudinal cross-sectional view of the ceramic stalk attachment part, in which a cast iron cylindrical lower bracket 5 is placed on the lid step 2 provided on the lid 1 via a packing 11. Two steps are provided, the lower step is in contact with the lower surface of the circular brim-shaped flange 4 provided near the upper end of the ceramic stalk 3 via the packing 12, and the upper step is in contact with the outer peripheral surface of the flange of the ceramic stalk and the lower bracket. This serves as a support surface for a sealing material 6 for gas sealing inserted between the inner circumferential wall and the inner circumferential wall. The upper bracket 7 is provided with an annular protrusion 8, and the upper bracket and the lower bracket are connected by tightening bolts 9 through bolt holes provided at appropriate intervals in the upper bracket. 8 presses the upper peripheral surface of the sealing material 6 for gas sealing to maintain airtightness. The bolt head after tightening is sunk below the upper surface of the upper bracket, and the intermediate stalk 10 made of cast iron or ceramic is attached to the packing 13 by the upper bracket.
It is designed so that a required distance t is maintained between the upper end surface of the ceramic stalk, the lower bottom surface of the intermediate stalk, and the upper surface of the upper support fitting. In the figure, 14 indicates a molten metal.

<Operation> Since the present invention has the above-mentioned structure,
Even if the intermediate stalk is deformed, the required distance is maintained between the upper bracket and the intermediate stalk surface, so there is no fear that the inner peripheral edge of the intermediate stalk will exert bending stress on the ceramic stalk. Furthermore, when the sealing material that maintains airtightness and absorbs intermittent impact forces from above is pressed, it acts as a centripetal compressive force on the outer peripheral surface of the thick flange of the ceramic stalk. Ceramics have very high compression resistance, so there is very little risk of breakage due to compression.

<Effects of the invention> According to the invention, even if the intermediate stalk is deformed, it does not act on the ceramic stalk, and the pressure from above acts on the thick flange part as compressive force, making it difficult to break. This fully demonstrates the usefulness of ceramic stalks in low-pressure casting equipment.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view of a main part of an embodiment of a low-pressure casting apparatus according to the present invention, and FIG. 2 is a longitudinal cross-sectional view of a main part of a conventional apparatus. 1... Lid, 3... Ceramic stalk, 4...
...Flange portion, 5...Lower bracket, 6...Sealing material, 7...Upper bracket, 8...Annular protrusion, 9...
Tightening bolt, 10...Intermediate stalk, 11,1
2, 13... Packing, 14... Molten metal, t... Interval between intermediate stalk and ceramic stalk.

Claims (1)

[Scope of utility model registration request] The molten metal in the holding furnace sealed by the lid is connected to the mold above the lid via a ceramic stalk and an intermediate stalk, and the molten metal is press-fitted into the mold by air pressure acting on the molten metal surface to perform casting. In the casting structure, a flange portion is formed near the upper end of the ceramic stalk,
The lower surface of the flange is supported by the stepped portion of the lower bracket set on the seat of the lid, a sealing material is inserted between the outer periphery of the flange and the inner wall of the lower bracket, and the sealing material is attached to the lower bracket. A low-pressure casting apparatus using a ceramic stalk, characterized in that the intermediate stalk is pressed by an upper receiving fitting coupled to the ceramic stalk, and the intermediate stalk is supported by the upper receiving fitting, and a required distance is maintained between the stalk and the end face of the ceramic stalk.