JPH06190494A - Production of transparent casting mold - Google Patents

Abstract

PURPOSE:To rapidly form a transparent casting mold having intricate shapes with simple operation by embedding a wax pattern model into a photosetting resin compsn. and curing this photosetting resin compsn. by irradiating with light, then heating the wax pattern model to melt, thereby allowing the wax to flow out. CONSTITUTION:The photosetting resin compsn. or more preferably UV curing resin compsn. is put into a transparent container having light transmissivity in a dark room. The wax pattern model is embedded therein and is subjected to a degassing treatment at need and is then irradiated with light, by which the photosetting resin compsn. is cured; thereafter, the wax pattern model is heated to melt until the wax flows out. The curing time is shorter and the calorific value per unit time associated with the curing is larger as the quantity of light for curing the photosetting resin compsn. is larger. As a result, the misrun and gas inclusion defect in casting are controlled by observing the inside of the transparent casting mold by a water model to recognize the fluid condition of the molten metal in the casting mold.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a transparent mold used in a water model experiment for recognizing the flow state of molten metal in a mold in precision casting and the like.

[0002]

2. Description of the Related Art In casting, particularly in precision casting of complicated shape, it is necessary to recognize in detail the flow state of the molten metal in the mold in order to control defects around the molten metal and gas entrainment. However, since the mold used for casting is opaque and its flow condition cannot be visually observed, a transparent mold molded with a transparent resin such as acrylic resin is used instead of the mold, and ink such as ink is used instead of the molten metal. I am trying to experiment with the water model. Then, by observing and analyzing the behavior of the filling of the India ink in the experiment with this water model, the flow state of the molten metal is predicted, the countermeasures for casting defects are taken, and it is useful for the production of the mold used for casting. .

[0003]

However, in the method of producing a transparent mold by molding a transparent resin such as the acrylic resin, the more complicated the cavity shape in the mold, the more difficult the molding process is, which is extremely troublesome. It required processing and a huge amount of time.

On the other hand, there is also a method of solidifying the transparent resin liquid by burying the wax type model in the transparent resin liquid and adding a curing agent. However, since the viscosity of the resin liquid is relatively high in this method, degassing is performed. The treatment is difficult and time-consuming, and if the degassing is not sufficient, the produced mold may not be transparent. Further, in this case, the wax model is melted due to the heat generated when the resin is cured, and there is a limitation that the wax model cannot be used.

[0005]

The present invention has been proposed in view of the above, and a wax type model is embedded in a photocurable resin composition and irradiated with light to cure the photocurable resin composition. rear,
The present invention relates to a method for producing a transparent mold, characterized in that a wax model is melted by heating and allowed to flow out.

As the wax model used in the present invention, the wax model used for general precision casting such as wax and resin can be used as it is. Further, in order to improve the wettability with the photocurable resin composition, a surfactant or an inorganic sol may be applied to the surface of the wax model.

The photocurable resin composition used in the present invention may be radical type or cation type as long as it can be photopolymerized, and the resin may be acrylic type or epoxy type, and other oligomers and additives. There is no particular limitation on the above. That is, an ultraviolet ray or electron beam curable resin composition may be appropriately combined with an initiator, a monomer, an oligomer, an additive and the like. The heat distortion temperature of the photocurable resin composition photocured is not particularly limited, but is preferably 65 ° C. or higher.

Specifically, the method for producing a transparent mold of the present invention comprises placing a photocurable resin composition, preferably an ultraviolet curable resin composition, in a transparent container having light transparency in a dark room. The wax-shaped model is embedded in the resin, and after degassing if necessary, the photocurable resin composition is cured by irradiating with light, and then the wax-shaped model is heated and melted to flow out. It is a thing.

The degassing treatment may be carried out by a known method of applying vibration, a method of utilizing reduced pressure, or the like. However, since the photocurable resin composition generally has a low viscosity, it is particularly long. It can be easily degassed without the need for time treatment.

Regarding the curing of the photocurable resin composition by light irradiation, the light source used, the amount of light, and the curing time are not particularly limited, but the curing time becomes shorter as the amount of light increases, and the curing unit The amount of heat generated per hour increases. 100 cc for curing using sunlight as an example
It is recommended to cure the above resin by exposing it to sunlight for about 2 hours. A laser beam or the like is generally used as the light source. The amount of heat generated during curing can be controlled by the strength of the light source and the light irradiation time. At that time, the amount of heat generated by curing may be absorbed by interposing water or the like in the surroundings to suppress the temperature rise.

Further, in order to melt the wax-shaped model by heating and let it flow out, it may be carried out, for example, by immersing it in hot water at 60 to 80 ° C. In particular, when the melted liquid that has been heated and melted is difficult to flow out, such as when the wax model has a complicated shape, supply a volatile organic solvent such as ethanol, acetone, or xylene into the cavity of the transparent mold. The operation of washing with water and the operation of supplying hot water for elution may be repeated.

Further, after the wax model is completely eluted,
The inside of the formed mold cavity is sufficiently dried, and if necessary, the photo-cured resin surface is polished to prepare the transparent mold of the present invention.

As described above, according to the present invention, even when a sufficient time is taken for photocuring and drying, for example, the transparent mold is extremely quicker than the conventional method of molding the acrylic resin to form the transparent mold. Can be made for 2 hours
It's about a day.

The prepared transparent mold can be used for experiments in the water model, etc., and the behavior of the filling of ink or the like can be observed and analyzed to predict the flow state of the molten metal, By taking measures against casting defects, it can be useful for producing a mold used for casting.

[0015]

EXAMPLES Examples of the present invention will be shown below.

Example 1 40 g of a wax model (impeller shape for turbocharger, minimum wall thickness 1 mm) having a three-dimensional complex shape was buried in 120 cc of a photocurable resin composition (SCR-400 manufactured by DEMEC Co., Ltd.), After degassing in a reduced pressure atmosphere (-500 mmHg), it was exposed to sunlight in a water tank for 2 hours to be photocured. 7 after curing
The wax model was eluted in hot water at 0 ° C., and the inside of the mold cavity was washed with 50 cc of acetone to remove the residual wax in the details of the wax model. Then, after naturally drying, a model test of hot water flow using India ink was performed.

Although the transparent mold produced as described above had a light brown color, it was accurately reproduced up to a portion having a wall thickness of 1 mm. Then, in the hot water model experiment, it was possible to observe the filling behavior of the India ink in the mold.

[0018]

As described above, according to the present invention, a transparent mold having a complicated shape can be rapidly manufactured by an extremely simple operation without requiring a special device or a skilled technique. Then, by filling a water model such as India ink in the obtained transparent mold and observing its behavior, it is possible to recognize the flow state of the molten metal in the mold and control the hot melt and gas entrainment defects in casting. can do.
Therefore, it is possible to easily take countermeasures against casting defects that have been performed by thought and error in the past, and it is possible to reduce the time required for producing a mold as a whole, and industrially useful effects such as reducing the cost for producing a mold. Be brought.

Claims (1)

[Claims] 1. A wax model is embedded in a photocurable resin composition and irradiated with light to cure the photocurable resin composition,
A method for producing a transparent mold, characterized in that a wax model is melted by heating and allowed to flow out.