JPS6182949A - Precision casting method - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a precision casting method, more specifically to precision casting performed by a loft wax method, and particularly to a one-way casting method.

(Prior art) ゛ In rectification casting performed by the loft wax method, the one-way casting method is such that the runner, weir 2, and precision casting model are integrated using a wax made of urea resin, urea resin, etc. A single tree is molded by injection molding, and colloidal silica is applied around the tree.
Coating the zircon with a sticky liquid,
Furthermore, ceramic coating is performed by repeating the process of coating with alumina sand T and drying (natural drying) several times.

Next, a ceramic coated tree alone?
Charged into the heating chamber at a pressure of 5 kti/cd and a temperature of 145
A mold is formed by heat treatment using C steam and dewaxing treatment to melt and flow out the wax tree itself, and then firing treatment for 2.5 hours in a heating furnace at a temperature of 1000℃. Then, the molten metal is poured into this mold, and after cooling, the mold is broken up and removed by hammering or vibration with a vibrating device, and the weir is then broken up and removed from the cast product to obtain the M relic.

In the above-mentioned one-piece casting method, the model is supported by a runner through a weir, and the cross-sectional area and thickness of the weir are set according to the size and shape of the model.

In other words, in general, if J (m2) is small, it can be supported by one weir extending from Yuyama, and the model is large J4.
The bridge is supported by two or more weirs extending from the runner, as in Japanese Patent Publication No. 58-49344, for example.

As a result of the dewaxing process, the mold surrounding the space where the model has flowed out can be used to remove the space where the runners have flowed out through the mold surrounding the space where the multiple weirs have flowed out. It is supported by the mold of the surrounding part. Therefore, even if the model flows out and molten metal that is to become a cast product is poured into the fc dug, it is stably supported.

However, in such a method in which the model is supported by a plurality of weirs, the work of removing the filler metal from the cast product after casting is troublesome, and the dismantling performance is poor. Moreover, there is a problem that the cast product may be damaged during disassembly work.

Therefore, even in the case of a large model, a method of supporting it with a single weir can be considered, but by performing dewaxing treatment, the model can be placed in the space where the model has flowed out by using the mold that surrounds the space where one weir has flowed out. It is extremely difficult to stably support the molten metal that is to be cast, the molten metal that is to become the cast product, and it is not possible to ensure the full precision of the cast product.

(Purpose of the Invention) This invention was made to solve the above-mentioned conventional problems, and aims to improve the ease of dismantling the weir from the cast product, and to stably support all of the molten metal cast into the model outflow space. An object of the present invention is to provide an M-tight casting method that guarantees the precision of a cast product.

(Structure of the Invention) In order to achieve the above object, the present invention involves forming a tree structure by integrally molding a runner, a weir, and a model using wax, and then applying a ceramic coating to the periphery of this structure. This is a method of casting by firing and pouring out the wax, in which a protruding step part is formed in the runner to protrude toward each model during the molding process, and during ceramic coating, the protruding step part and The model is connected to the model by ceramic, and the model is combined with the mold of the part surrounding the space where the weir has flowed out, the mold of the part of the protruding step surrounding the space where the projecting step has flowed out, and the ceramic of the connection part. The weir is designed to stably support the molten metal being cast into the space, and to improve the dispersion of the weir from the cast product.

(Example) Embodiments of the present invention will be described below with reference to the drawings.

In Figure 1, 1 is a single tree, and this single tree 1
The runners 2, weirs 3, and precision casting models 4 are molded using wax such as urea resin or urea resin.
4 are integrally formed by injection molding.

When modeling the above tree single unit 1, each model 4, 4 from the runner 2
A protruding step portion 6 is formed which protrudes toward the model 4° and faces the model 4°4 with a gap 5 therebetween.

Next, a process of coating with a liquid made of colloidal silica, fused silica, zircon, etc., followed by sanding with alumina sand and drying (natural drying).
- Repeat several times (e.g. 8 times) to form a ceramic coating layer 7 as shown in FIG. As a result, the ceramic 7a is interposed in the gap 5 (FIG. 1) between the protruding step 6 and the replacement mold 4.4, and the ceramic 7B
and the models 4, 4 are connected, and the model 4.4 is connected to the weir 3,
Both of the protruding step portion 6 and the combined body 8 of the ceramic 7a 3.8
Supported by

Next, it is charged into a heating chamber at a pressure of 5 kq/d and a temperature of 14
A heat treatment is performed using steam at 5° C., and a dewaxing treatment is performed in which the wax tree 1 is melted and flowed out as shown in FIG. Then, a mold 10 having a space 9 having the same volume as the tree 1 is formed by firing in a heating furnace at a temperature of 1000° C. for 2.5 hours.

Furthermore, molten metal 11f: casting (
(Fig. 4), after cooling, it is cast by hammer pressure or vibration with a vibrating device, WIO? After being disassembled and removed, a metal tree with the same volume as the above-mentioned single tree 1 is made as shown in Fig. 5! +-1A'.

By carrying out the above dewaxing process, the mold 10B in the part surrounding the night 98 in Fig. 3 from which the model 4.4 in Fig. 1 has flowed out, and the space gbl from which the weir 3 (Fig. 1) has flowed out. Space 9 where the mold job of the part and the loading step 6 (Fig. 1) have flowed out
A mold 10e of a portion surrounding C is formed, and the above-mentioned models 4,
The part of the mold 10B surrounding the space 9a' where 4 has flowed out is as follows:
Space 9b where weir 3 leaked out? A surrounding part of the mold 10b,
Mold 10 surrounding the space 9Ct from which the protruding step 6 has flowed out
The mold 10 of the part surrounding the space 9dffi from which the runner 2 (Fig. 1) has flowed out through both 10b and 8A'e of the combined body 8A of the ceramic 7a and the gap 5 (Fig. 1) K formed between C and the gap 5 (Fig. 1)
It is supported by d.

Therefore, even if the molten metal 11 is cast into the space 911C from which the models 4 and 4 in FIG. Ru.

In addition, when removing the 4M mold 10' (1),
Since the mold 10 made of ceramic has low adhesion to metal, it is easily broken apart and removed by hammer pressure or vibration by a vibrating device, as shown in FIG.
A metal tree LA' can be obtained with an interval Vfi5a.

Therefore, since each of the cast products 12 is supported by only one weir 3a, the disassembly of the weir 3a is improved, and the cast products 12t are not damaged.

(Effects of the Invention) As explained above, according to the precision casting method of the present invention, the ease of dismantling the weir from the cast product is improved, and
The molten metal that is cast into the model outflow groove is stably supported, ensuring the accuracy of the cast product.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing an example of a single wax tree applied to the precision casting method according to the present invention, FIG. 2 is a cross-sectional view showing a state in which a ceramic coating layer is formed on the wax tree alone, and FIG. Figure 4 is a cross-sectional view showing the state in which molten metal has been poured into the mold, and Figure 5 is a cross-sectional view showing the state in which molten metal has been poured into the mold. FIG. 3 is a front view of the metal tree. 1... Tree music, 2... Hot water path, 3... Weir, 4.
4...Model, 6...Protruding step portion, 7...Ceramic coating, 7a...Ceramic. 11th<1

Claims (1)

[Claims] (1) After forming a single tree by molding the runner, weir, and model into one body using wax, apply a ceramic coating around this single body, fire it, pour out the wax, and cast. The method includes forming a protruding step portion protruding toward each model in the runner during the molding,
A precision casting method characterized in that, during ceramic coating, the protruding step portion and the model are connected by ceramic.