JPS6354467B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a half-lost wax casting method in a precision casting method using a fugitive model.

[Related technologies and problems]

In the conventional precision casting method, a master mold formed by compensating for the shrinkage of the metal is covered with an elastic mold made of silicone rubber, etc. After hardening, the master mold is taken out of the mold made of silicone rubber, etc., and then placed inside the cavity. A fugitive model is molded by injecting or pouring wax, resin, etc. After curing, the fugitive model is taken out of the silicone rubber mold, a sprue runner and an air vent are attached to the fugitive model, and cristobalite, zircon sand, alumina, etc. A precision casting mold is manufactured by immersing it in a refractory or coating it with a refractory slurry, and then the fugitive model is removed from the mold and metal is cast in the cavity formed.
In this way, precision casting molds have been manufactured by attaching sprue runners, air vents, etc. to a fugitive model and then forming a refractory shell layer over the entire surface of the model by burying or coating the model. However, in such conventional precision mold manufacturing methods, a fugitive model is formed by injecting or pouring wax, resin, etc. into a cavity in a mold made of silicone rubber, etc., so the correction accuracy for metal shrinkage is low, and When removing a mold made of silicone rubber or the like from a fugitive model, some molds such as silicone rubber tend to be easily deformed. In addition, since the refractory shell layer is formed after sprue runners and air vents are attached to the fugitive model, it is necessary to form the sprue runners and air vents for fugitive model molding each time, resulting in low workability. Ta.

[Purpose of the invention]

The present invention was made in view of the above-mentioned object, and one side is fixed with a precision-guaranteed mold,
Because it is an elastic mold made of silicone rubber or the like on only one side, it has good accuracy, prevents deformation of the fugitive model when removing the silicone rubber mold, and eliminates the need to provide sprues or the like on the fugitive model. The purpose of this invention is to provide a half-lost wax casting method that has two advantages.

[Summary of the invention]

The half-lost wax casting method for achieving the above purpose involves forming a fugitive model with a sprue etc. between a semi-mold made of refractory material and an elastic mold, and then only the elastic mold is used. Fixing and molding a fugitive model with a sprue etc. on a half mold that is removed and formed from a refractory, and coating the semi-fixed fugitive model with a slurry made of a refractory or burying it in the refractory to produce a mold. It is in.
Note that the half-mold refers to a mold on one side of the fugitive model, and its size is not limited to half of the entire mold, and may be selected as appropriate.

[Embodiments of the invention]

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

One side of a prototype having an air vent and sprue runner (not shown) on the side where the air vent and sprue runner are located is covered with a half mold 1 made of refractory material, and the other side is covered with an elastic mold 2 made of silicone rubber, etc., and after curing, As shown in FIG. 1, a fugitive model 6 is molded by injecting or pouring wax, resin, etc. into a cavity 5 having an air vent 3 and a sprue runner 4 formed on the side of a half-mold 1 made of refractory material by taking out the model, as shown in FIG. After curing, only the mold 2 made of silicone rubber or the like is removed, and a fugitive model 6 having an air vent 3 and a sprue runner 4 is fixedly molded on a semi-mold 1 made of refractory material as shown in Fig. 2, and then it disappears as shown in Fig. 3. A refractory shell layer 7 is formed integrally with the refractory half mold 1 by coating the exposed part of the refractory model 6 with a refractory slurry or immersing it in the refractory, and after hardening, a precision mold 8 is formed by a conventional method. A product 11 shown in FIG. 6 is obtained by a conventional method by taking out the fugitive model 6 and injecting a metal material 10 into the formed cavity 9 as shown in FIG. 5. Note that the mold 2A made of silicone rubber or the like covers the side of the half-mold 1 made of refractory material;
The projections 12 prevent mold displacement. 13
is the injection inlet. Therefore, in the above embodiment, the fugitive model 6 is molded between the elastic mold 2 made of silicone rubber or the like and the semi-mold 1 made of refractory material, and the fugitive model 6 is formed between the mold 2 made of silicone rubber or the like.
Remove the air vent 3 and sprue runner 4
A fugitive model 6 having a semi-mold made of refractory material 1
The refractory shell layer 7 is formed integrally with the refractory half-mold 1 in this state to produce the precision mold 8, so the master of the desired casting is faithfully reproduced. Since the precision mold 8 can be manufactured without removing the fugitive model 6 from the semi-precision mold 1 made of refractory material, the contraction and expansion of the semi-mold 1 made of refractory material is calculated and the metal shrinkage is plus or minus 0. By molding the half-mold 1 with the dots exposed, high accuracy can be obtained, and deformation of the half-mold 1 to which the fugitive model 6 is fixed can be prevented at the stage of embedding it in a refractory. Therefore, by using the semi-mold 1 made of a refractory material on the precision structure side of the product 11 or the side having an undercut, a highly accurate product can be obtained. In addition, since an air vent 3 and a sprue runner 4 for metal casting are formed in the semi-mold 1 made of refractory material, the fugitive model 6 is formed using the air vent 3 and sprue runner 4.
can be formed well, and there is no need to attach the air vent 3 and sprue runner 4 to the fugitive model 6, making production easy.

〔Effect of the invention〕

The present invention involves molding a fugitive model having a sprue etc. between a half-mold made of a refractory and an elastic mold, and then removing only the elastic mold to form a half-mold made of a refractory. A fugitive model with a sprue, etc. is fixedly molded on the mold, and a slurry made of a refractory is coated on the semi-mold fixed fugitive model or a slurry made of a refractory is buried in the refractory to produce a mold. To provide a precision half-lost wax casting method which can prevent deformation of a fugitive model when removing a mold such as the above, and eliminates the need to provide a sprue runner and an air vent to the fugitive model.

[Brief explanation of the drawing]

1 to 6 show embodiments of the present invention.
The figure is a vertical cross-sectional view of the fugitive model molded, Figure 2 is a vertical cross-sectional view with the elastic mold made of silicone rubber etc. removed, and Figure 3 is a vertical cross-sectional view of the mold made of refractory material. , FIG. 4 is a longitudinal sectional view of the product with the fugitive model removed, FIG. 5 is a longitudinal sectional view of the cast metal, and FIG. 6 is a longitudinal sectional view of the product. 1... Half mold made of refractory material, 2... Elastic mold, 3... Air vent, 4... Sprull runner, 6... Disappearance model, 8... Precision mold.

Claims (1)

[Claims] 1. Molding a fugitive model with sprues etc. between a semi-mold made of refractory material and an elastic mold,
After that, only the elastic mold is removed and a fugitive model with a sprue etc. is fixedly molded on a half mold made of refractory, and the half mold fixed fugitive model is coated with a slurry made of refractory or refractory. A half-lost wax casting method, characterized in that a mold is manufactured by burying the wax, and then the semi-mold-fixed fugitive model is extracted to manufacture a mold.