JPH0255657A - Method for casting ceramic cast-in material - Google Patents

Abstract

PURPOSE:To save shot blasting for shake-out of molding sand after casting by accompanying heat vaporizing plastic layer with wall surface of hollow ceramic member having opening part, connecting sprue member with this and embedding in permeable sand. CONSTITUTION:Polystyrene layer 2 as the heat vaporizing plastic layer having the prescribed thickness is arranged along the outer wall face of cylindrical ceramic member 1 as the hollow ceramic member having the opening part. The polystyrene-made sprue member 3 having the same material as the above, is pasted and these are embedded in the permeable drying sand 5 in the vessel 4. Then, the upper end of the member 3 is made to almost the same level as the upper face of the sand 5. Successively, at the time of pouring molten metal through the member 3, the member 3 is vaporized and disappeared and further, the layer 2 is disappeared as the same way as the member 3, and the molten metal is filled up into the disappeared space. The vaporized gas of the layer 2 and the member 3 is exhausted through the sand 5. As the sand 5 is dried, even if the sand is stuck to the cast-in product, it can be easily shaken out.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for casting a ceramic cast article, in which a metal layer is formed along the wall surface of a hollow ceramic member.

[Conventional technology]

Conventionally, when casting ceramic castings, an outer mold and a core are used, but the sand used as the constituent material for these outer molds and the core is mixed with a binder. Therefore, it is necessary to use a shot (small steel ball) to remove sand after casting.

[Problem to be solved by the invention]

By the way, in the conventional casting method as described above, when a shot is applied to remove sand, there is a risk that the ceramic member in the ceramic casting product may be destroyed by the shot.

The present invention is an attempt to solve these problems, and aims to provide a method for casting ceramic castings that does not require sand removal after casting. do.

[Means to solve the problem]

In order to achieve the above-mentioned object, the method for casting a ceramic cast product of the present invention first involves the above-mentioned process when casting a ceramic cast product in which a metal layer is formed along the wall surface of a hollow ceramic member having an opening. A heat-evaporable plastic layer in the shape of a casting is attached to the wall surface of the ceramic member, and a sprue member is connected to the plastic layer, and then the ceramic member is placed in air-permeable dry sand. It is characterized in that after being buried together with the plastic layer, molten metal is injected through the sprue member to replace the molten metal with the plastic layer.

[For production]

In the above-described method for casting ceramic castings of the present invention,
The molten metal injected through the sprue member is introduced into the heat-evaporable plastic layer along the wall surface of the ceramic member, and its high temperature acts to evaporate the plastic layer.

Then, the molten metal replaces and fills the space where the plastic layer has disappeared. The evaporated gases of the plastic layer are then discharged through the air-permeable dry sand.

Ceramic castings cast in this manner do not need to be shot because dry sand can be easily removed even if it adheres to it.

〔Example〕

Hereinafter, a method for casting a ceramic casting product as an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a longitudinal cross-sectional view showing the state before molten metal is poured during casting.

In the method for casting a ceramic casting product of this embodiment, a cylindrical ceramic member 1 is used as a hollow ceramic member having an opening, and a polystyrene film as a heat-evaporable plastic layer of a required thickness is formed along the outer wall surface of the cylindrical ceramic member 1. Layer 2 is provided.

A sprue member 3 made of the same polystyrene is glued to this polystyrene layer 2.

In this way, the polystyrene layer 2 in the shape to be cast is deposited on the wall surface of the ceramic member 1 to be cast with a required metal material, and then the polystyrene layer 2 is layered with air-permeable dry sand 5 in the container 4I. An operation is performed to bury the body inside.

At this time, the upper end of the sprue member 3 is set at approximately the same level as the upper surface of the dry sand 5.

Next, when the required molten metal is injected through the sprue member 3, the sprue member 3 made of polystyrene evaporates and disappears due to the high temperature of the molten metal, and is replaced by the molten metal.
The molten metal is further introduced into the polystyrene layer 2.

Along with this, the polystyrene layer 2 also evaporates and disappears due to the high temperature of the molten metal, and the molten metal replaces and fills the space where the polystyrene layer 2 has disappeared.

Then, the evaporated gas from the polystyrene layer 2 and the sprue member 3 is discharged to the outside through the air-permeable dry sand 5.

In this way, a ceramic casting product in which a metal material is cast into the wall of the hollow ceramic member L is cast, but since the dry sand used for this casting is smooth and breathable, the ceramic casting Even if it adheres to stuffed goods, it can be easily removed.

Therefore, the conventional work of spraying shot to remove sand can be omitted, and damage to the ceramic member 1 due to the shot can also be prevented.

Note that the sprue member 3 does not necessarily have to be a heat-evaporable plastic member, and may be a normal funnel-shaped heat-resistant member.

〔Effect of the invention〕

As detailed above, according to the method for casting ceramic castings of the present invention, there is no need to apply a shot to remove sand after casting, which prevents damage to the ceramic components and simplifies the work. There are benefits it brings.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view showing a state before molten metal is poured during casting according to a method for casting ceramic castings according to an embodiment of the present invention. 1. Ceramic member, 2. Polystyrene layer as heat-evaporable plastic layer, 3. Sprue member, 4. Container, 5. Dry sand.

Claims (1)

[Claims] When casting a ceramic casting product in which a metal layer is formed along the wall surface of a hollow ceramic member having an opening, first a heat-evaporable plastic layer in the shape to be made into a casting is attached along the wall surface of the ceramic member. At the same time, a sprue member is connected to the plastic layer, and then the ceramic member is buried together with the plastic layer in air-permeable dry sand, and the molten metal is injected through the sprue member to drain the molten metal. A method for casting a ceramic casting product, characterized by replacing the plastic layer with the above-mentioned plastic layer.