JPS6239874Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a mold for making a mold, which is capable of reinforcing a fugitive model and holding it fixedly during mold making.

FIGS. 1a and 1b are general views showing an example of a mold for casting a cast product having a shape that requires a fugitive model. In this mold, a main mold 1 consists of an upper mold 1a and a lower mold 1b, each of which is surrounded by a mold frame 2, and a sprue 3 is provided on the upper surface of the upper mold 1a. The poured molten metal passes through a runner 4, passes through a weir 5, and flows into a casting space 6. Further, a gaiter 7 is provided in the casting space 6 so that air can be vented well. Further, in the casting space 6, a mold, that is, a core 9, enclosing the fugitive model 8 is disposed, and is held in a predetermined position by a mold support 10.

In such an apparatus, when molten metal is poured from the sprue 3, the molten metal flows into the casting space 6 through the runner 4 and the weir 5, and the fugitive model 8 is formed by the heat of the molten metal.
vaporizes and disappears, casting space 6 and disappearing model 8
After the molten metal is filled into the area, it solidifies and becomes a cast product.

FIG. 2 is a three-sided view and a perspective view showing a cast product cast using the above-mentioned mold. Furthermore, the central block portions 14 are each formed by the disappearance of the evanescent model 8. Note that the hole 15, which is the mark of the mold support 10, becomes an opening for taking out the core 9 after casting.

In a conventional mold for casting a cast product having the shape described above, first, in order to manufacture the core 9, as shown in FIG. The fugitive model 8 is set in the mold 19, and a core material such as foundry sand is blown into the mold 19 to form the core 9. , vanishing model 8
Because the structure lacked positioning and fixing means, the position of the fugitive model 8 set in the mold 19 was not very accurate, and even if it was set in the correct position, sand would be blown into the core 9. There is a problem in that positional deviation occurs during the process of molding the core 9, and as a result, it may not be possible to mold the core 9 with high precision. Furthermore, since the evanescent model 8 is molded from a relatively fragile material, it has the problem that thin parts, in particular, may be deformed or damaged by the filled sand. Ta.

This invention was made by focusing on these conventional problems, and it is possible to prevent the deformation and damage of the fugitive model, and to create a mold that has a shape that wraps the fugitive model in an accurate manner. The object of the present invention is to provide a mold for mold making that can be easily produced.

Hereinafter, embodiments of this invention will be described in detail based on the drawings.

FIGS. 4 to 6 are diagrams showing each embodiment of this invention.

In the embodiment shown in FIGS. 4a and 4b, the mold making mold 25 is divided into an upper side 25a and a lower side 25b, and the upper mold 25a has holes 2 for injecting core sand.
1 is open. Furthermore, two rod-shaped reinforcing members 26 are erected at the bottom of the lower mold 25b. In this mold 25, the fugitive model 27 can be fixed and held by piercing the reinforcing member 26 with a protrusion 27' formed on the lower surface of the fugitive model 27.
In this way, the core sand is blown into the hole 21 using air pressure or the like to produce a core that encases the fugitive model 27. The core can be molded with high precision without shifting. Furthermore, in this structure, since the reinforcing member 26 plays a role of reinforcing the fugitive model 27, deformation and breakage can be prevented, especially in the case of a thin fugitive model 27. In addition,
It is also desirable to make a hole in advance in the protrusion 27' of the fugitive model 27, into which the reinforcing member 26 is inserted.

Mold 3 for mold making according to the embodiment shown in FIGS. 5a and 5b
0, the upper mold 30a is the same as the embodiment shown in FIG. 4, but the lower mold 30b has holes 31 on both sides.
a, 31b are drilled, and the holes 31a, 31b
Rod-shaped reinforcing members 32a and 32b that are moved by an air cylinder (not shown) or the like are passed through the holes. In this mold 30, after the fugitive model 33 is set, the protrusions 33a, 33 formed on both sides of the fugitive model 33 are
By inserting the reinforcing members 32a and 32b in the direction of arrow A, the fugitive model 33 can be fixedly held, and at the same time the fugitive model 33
can be reinforced. Note that it is preferable to make holes in advance in the protruding portion of the disappearing model 33 into which the reinforcing members 32a and 32b are inserted.

Mold 4 for mold making according to the embodiment shown in FIGS. 6a and 6b
0, the upper mold 40a has a slightly deeper core mold 41 than the upper mold of the above-mentioned embodiments,
Fixing recesses 42a, 42 are provided inside the lower side 40b.
b, 42c are provided. Further, a reinforcing member 44b having a protruding tip is embedded in a protrusion 43b formed on the lower surface of the evanescent model 43.
A reinforcing member 44a having both ends protruding is embedded in a and 43c so as to pass through them. In the above-described configuration, the evanescent model 43 connects the protrusions of the embedded reinforcing members 44a, 44b to the fixing recesses 42a, 42b, 42c of the lower mold 40b.
They are fixedly held in the mold 40 by being pressed from above with the upper mold 40a. Further, the use of the reinforcing members 44a and 44b helps prevent deformation and damage of the fugitive model 43, leading to improved precision of the casting. Note that the reinforcing member 44a,
44b is removed when the fugitive model is removed after core formation.

If a plurality of the embodiments shown in FIGS. 4 to 6 are combined, the reinforcing, positioning, and fixing of the fugitive model in the casting mold will become more reliable.

As explained above, according to this idea,
A mold for producing a mold having a shape of integrally enclosing a fugitive model, comprising a reinforcing member inserted into the fugitive model to fix the fugitive model to the mold for mold production. Therefore, the positioning of the fugitive model with respect to the mold becomes accurate, and it is possible to prevent the fugitive model from being deformed or damaged during the molding process of the mold having a shape that wraps around the fugitive model, and as a result, This has the excellent effect of making it possible to obtain cast products with higher precision, and also has the effect of being expected to improve efficiency in terms of workability.

[Brief explanation of the drawing]

Figures 1 a and b are a plan view and a cross-sectional view of a casting machine for casting a cast product, Figures 2 a to d are three side views and a perspective view of a cast product manufactured from the mold in Figure 1, and Figure 3
The figure is an explanatory cross-sectional view of a conventional mold-making mold, and Figs. 4 to 6 are explanatory views of each embodiment of this invention. An explanatory view of the state in which the mold is released, and b of each figure is an explanatory view of the state in which the fugitive model is fixed and held within the mold. 27, 33, 43... Vanishing model, 42a, 4
2b, 42c...disappearing model fixing recess, 26,
32a, 32b, 44a, 44b... reinforcing members.

Claims (1)

[Scope of utility model registration request] A mold for making a mold for making a mold having a shape that integrally wraps a fugitive model, comprising a reinforcing member inserted into the fugitive model to fix the fugitive model to the mold for mold making. A mold for mold making, which is characterized by: