JPS63264244A - Funnel for pouring molten metal - Google Patents

Abstract

PURPOSE:To easily manufacture what is corresponding to the gate opening port size of a sand mold and to prevent the decay of a casting sand by coating the refractory granular layer formed by the dried solidification of a refractory granular slurry on the inner peripheral face at least of the funnel for pouring molten metal made of paper. CONSTITUTION:A refractory granular layer 3 is formed by coating it on the whole peripheral face of a main body 2 of a funnel 1. The funnel main body 2 is adhered at its mating face by rounding a segmental thick paper in a truncated conical shape, a molten metal gate 4 is formed at the upper end and the molten metal flowdown port 5 about in the same diameter as that of a mold gate is formed at the lower end. A refractory granular slurry is coated on the funnel main body 2 to solidify the refractory granular layer 3 by its drying. In succession, the funnel 1 is set up at the opening part of a gate model 14 of a sand mold casting to effectively prevent the decay of a casting sand 13 of the opening part at the molten metal pouring time. A molding die is unnecessary and any optional product can be manufactured at low cost irrespective of the size of the funnel 1.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a pouring funnel used to prevent the sprue opening of a sand mold from being partially collapsed by the flow of poured molten metal. .

(Conventional techniques and their problems) In casting methods that use a sand mold made of casting sand that does not contain a binder, so-called dry sand, such as the vanishing model casting method and the vacuum casting method, when pouring, the sand mold The sprue opening of the mold is easily collapsed by the flow of molten metal, and once it collapses, the collapsed casting sand gets caught up in the molten metal, causing casting defects such as sand pits.

In order to prevent such casting defects from occurring, a pouring spout or dish bowl made of ceramic (mullite), self-hardening sand, or shell mold is often installed at the sprue opening.

However, these products cannot be easily manufactured to any size and require a mold for shaping, resulting in high molding costs, which in turn causes an increase in casting costs.

The present invention has been made in view of these problems, and it is an object of the present invention to provide a means for preventing casting sand from collapsing to a low degree, which can be easily manufactured regardless of the size of the sprue opening of a sand mold. purpose.

(Function) Since a layer of refractory powder particles is formed on at least the inner circumferential surface of the funnel body, 135
It has sufficient heat resistance even for high-temperature molten metal of about 0 to 1450°C, and does not collapse even though the funnel body is made of paper. Therefore, by installing the pouring funnel according to the present invention at the sprue opening of a sand mold casting, it is possible to effectively prevent the molding sand in the opening from collapsing during pouring.

In addition, the funnel body is made of paper, and the refractory powder layer formed at least on the inner circumferential surface of the funnel body is also coated with refractory powder slurry.
Since it can be easily formed by drying, there is no need for a mold for shaping as in the past, and any pouring funnel can be manufactured at low cost regardless of its size.

(Example) Next, an example of the pouring funnel of the present invention will be described with reference to the drawings.

FIG. 1 shows a truncated cone-shaped pouring funnel 1.
The funnel 1 has a funnel body 2 having the same shape and a layer 3 of refractory powder particles adhered to the entire circumferential surface of the funnel body 2.

The funnel body 2 is made by cutting cardboard into a fan shape, rolling it into a truncated conical shape, and bonding the mating surfaces together.A molten metal socket 4 is formed at the upper end, and a diameter approximately the same as that of the mold sprue is formed at the lower end. A molten metal flow outlet 5 is formed. The cardboard may be thick enough not to deform when handling the funnel main body 2, and suitable materials such as cardboard and Kent paper can be used.

The refractory powder layer 3 is obtained by applying a refractory powder slurry to the funnel body 2 and drying and solidifying it. Although Fig. 1 shows the funnel body 2 immersed in a tank of slurry, and the slurry applied to the entire circumferential surface and dried, a spray, a brush, etc. may be used as the application means, and the slurry may be only the inner peripheral surface of the funnel body 2 through which the molten metal passes.

The refractory powder slurry includes zircon sand, silica sand, graphite, coke, etc., which are used as base materials for coating molds.
It is possible to use a product in which colloidal silica, bentonite, etc. are added as a binder to a fine powder of about 50 mesh, and water is added to the mixture to form a slurry. Among the above, combinations of zircon sand, silica sand, and colloidal silica are preferred because they can form a refractory powder particle layer with excellent fire resistance.

The refractory powder particle layer 3 is formed to have an appropriate thickness depending on the pouring temperature and casting time, but usually a thickness of about 0.5 to 2 thick enables casting of small and medium-sized iron castings (about 50 kg or less).

In addition, if the strength or fire resistance of the refractory powder layer 3 is insufficient, it is better to use a layer of 35 to 48
It is preferable to apply a mesh size of casting sand such as silica sand to the undried slurry coating surface to form a casting sand layer, dry and solidify the slurry, and then form a refractory powder layer thereon again. This is because the casting sand layer acts as a core, increasing the strength improvement effect.

FIG. 2 shows an example of the use of the pouring funnel 1 of the present invention in a full mold casting method, in which a product model 12 made of foamed polystyrene or the like is placed in a metal frame 11, and dry sand 13 is placed around it. Filled. '14 is product model 1
This is the sprue model glued to 2.

(Effects of the Invention) As explained above, the pouring funnel of the present invention has a funnel body made of paper material, and refractory powder particles formed by drying and solidifying refractory powder slurry on at least the inner peripheral surface of the funnel body. Since the layer is coated, it is possible to easily manufacture a sand mold according to the sprue opening size, and there is no need for a shaping mold as in the conventional method, which reduces production costs. It is possible to reduce the

[Brief explanation of drawings]

FIG. 1 is a sectional view of a pouring funnel of the present invention, and FIG. 2 is an explanatory sectional view of a full mold casting mold showing an example of use of the funnel. DESCRIPTION OF SYMBOLS 1... Funnel for pouring molten metal, 2... Funnel body, 3... Refractory powder particle layer, 4... Molten metal socket, 5... Molten metal flow port.

Claims (2)

[Claims] (1) Drying refractory powder slurry on at least the inner peripheral surface of the paper funnel body 2, which has a molten metal inlet 4 at the upper end and a molten metal outlet 5 at the lower end, both of which are formed in a communicating manner. A pouring funnel characterized by being coated with a refractory powder particle layer 3 formed by solidification. (2) The pouring funnel according to claim 1, wherein another refractory powder layer is formed on the refractory powder layer 3 formed on the funnel body 2 via a casting sand layer.