JPH06114532A - Metal precision casting method and precision casting apparatus - Google Patents

Abstract

(57) [Summary] [Purpose] The refractory crucible can be easily replaced, and the molten metal melt during casting can be improved. Improve. A refractory crucible 32 is installed inside an induction heating cold crucible 31 to melt a metal by induction heating, and a molten metal 35 is suction-cast into a gas-permeable mold 43.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metal precision casting method and a precision casting apparatus used for efficiently melting and casting metal with high precision.

[0002]

2. Description of the Related Art When performing precision casting of metal, first of all, it is necessary to melt the raw material metal.
When melting this metal, the cupola, low frequency induction furnace,
Various furnaces such as a high frequency induction furnace, an arc furnace, and a plasma furnace are used.

Of these, the high-frequency induction furnace has a structure in which a high-frequency induction heating coil is arranged around a refractory crucible. In a normal high-frequency induction furnace, the coil is hardened with cement to protect it. Often, a refractory lining is applied to the inside to form a crucible made of refractory.

[0004]

Therefore, in such a high-frequency induction furnace, when it becomes necessary to replace the refractory crucible, the replacement of the refractory crucible becomes extremely complicated, and the heavy-duty work is difficult. Therefore, there is a problem that the melt-casting efficiency is hindered. Therefore, there is a problem to solve such a problem.

[0005]

DISCLOSURE OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and makes it possible to replace a crucible made of refractory material remarkably easily and at the time of casting. It is possible to improve the surroundings,
An object of the present invention is to provide a metal precision casting method and a precision casting apparatus capable of improving the melting and casting efficiency and the casting precision.

[0006]

The method for precision casting of metal according to the present invention comprises a refractory crucible mounted inside an induction heating cold crucible to melt the metal by induction heating to form a mold having air permeability. It is characterized in that the molten metal is suction-cast.

The metal precision casting apparatus according to the present invention comprises a melting section in which a refractory crucible is mounted inside an induction heating cold crucible, and a molten metal melted in the melting section into a breathable mold. It is characterized by having a configuration including a casting unit for suction casting, in the embodiment,
It is characterized in that the refractory crucible is made of at least one selected from oxides such as alumina, zirconia, magnesia, lime and yttria, and non-oxides such as boron nitride and graphite.

Further, in the metal precision casting apparatus according to the present invention, the refractory is formed by forming a draft between the induction heating type cold crucible and the refractory crucible mounted inside the cold crucible. It is also possible to further improve the attachability / detachability of the crucible to the induction heating type cold crucible.

[0009]

Since the metal precision casting method and the precision casting apparatus according to the present invention are configured as described above, the crucible made of refractory is reinforced by the induction heating type cold crucible and the crucible inside the cold crucible is also reinforced. It is easy to attach the refractory crucible to the cold crucible and take out the refractory crucible from the cold crucible.Since the casting is performed by vacuum suction, the hot water bath becomes good and the precision casting is highly accurate. Will be obtained with high efficiency.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an embodiment of a metal precision casting apparatus used for carrying out the metal precision casting method according to the present invention. Two
The melting section 3 and the casting section 4 are mainly provided.

Of these, an induction heating type cold crucible 31 is installed in the melting section 3, and a refractory crucible 32 is provided inside the induction heating type cold crucible 31.
Is attached.

The induction heating type cold crucible 31 is
An induction heating coil 3 is provided outside the water-cooled copper magnetic concentrator 311.
It has a structure in which 12 are arranged.

As shown in FIG. 2, the water-cooled copper magnetic concentrator 311 has a plurality of water-cooled copper segments 31 arranged in an annular shape so as to be insulated from each other by an insulator 310.
1a ... 311h, cooling water passages 313 are formed in the water-cooled copper segments 311a ... 311h, respectively, and the cooling water supplied from the direction of the arrow W _{1 in} FIG. After passing through the cold water passage 313,
It can be discharged in the direction of the arrow W _{2 in} FIG. 1.

This induction heating type cold crucible 31
The refractory crucible 32 installed inside the
It is made of at least one material selected from oxides such as alumina, zirconia, magnesia, lime and yttria, and non-oxides such as boron nitride and graphite. These materials are soluble metals and the like. It is better to select (depending on heat resistance, melting resistance, pollution resistance, etc., selection of conductivity and non-conductivity).

The melting section 3 has a melting section chamber 33.
Is installed, and the melting atmosphere can be made non-oxidizing by supplying an inert gas, for example, Ar gas, from the gas supply pipe 34 in the direction of the arrow A ₁ .

On the other hand, in the casting part 4, the casting part sleeve 4 formed integrally with the melting part chamber 33 of the melting part 3 is formed.
1, and a casting chamber 42 that can be moved up and down in the casting sleeve 41 in the arrow C direction and in the opposite direction, and a breathable mold 43 is installed in the casting chamber 42. In addition to this, the snout hollow tube 44 formed integrally with the air-permeable mold 43 can be positioned in the casting sleeve 41.

A gas communication pipe 46 is connected between the casting sleeve 41 and the melting chamber 33, and an inert gas such as Ar gas is supplied into the casting sleeve 41 to supply the casting sleeve. The inside of 41 is made non-oxidizable, and it can be discharged from the gas discharge pipe 47 in the direction of arrow A ₂ .

Further, a depressurizing gas suction pipe 48 is attached to the top plate portion of the casting chamber 42 so that gas can be sucked in the direction of arrow D during casting.

Furthermore, the melting part chamber 33, the casting part sleeve 41, and the casting part chamber 42 which are integrally formed together with the mold 43 having the air permeability on the surface plate 2 in the arrow B direction and the opposite direction. It has a slidable structure.

When melting and casting a metal with the metal precision casting apparatus 1 having such a structure, first, the metal raw material is charged into the crucible 32 made of refractory, and the Ar gas is supplied from the gas supply pipe 34. A non-oxidizing atmosphere is created inside the melting chamber 33 and the casting chamber 41 by supplying a gas or the like, and cooling water is flown into the cooling water passage 313 of the water-cooled copper magnetic concentrator 311 to perform induction heating. The coil 312 is energized.

As a result of this energization, as shown in FIG. 2, eddy current Is is generated in each water-cooled copper segment 311a ... 311h of the water-cooled copper magnetic concentrator 311 by high frequency induction heating by the coil current Ic of the induction heating coil 312.
Is formed, and the skin current If is induced in the metal raw material in the refractory crucible 32 by the eddy current that is an alternating current, and the metal raw material is melted to obtain the molten metal 35 in the refractory crucible 32.

Next, the melting chamber 33, the casting sleeve 41 and the casting chamber 42 are slid integrally on the surface plate 2 in the direction of arrow B to integrally form a hollow tube 44 in the air-permeable mold 43. Is stopped just above the refractory crucible 32.

Subsequently, the casting chamber 42 is lowered in the casting sleeve 41 in the direction of arrow C, the lower end of the hollow tube 44 is immersed in the molten metal 35, and the depressurizing gas suction pipe 48 is used to feed the arrow D. The molten metal 35 is sucked from the hollow tube 44 into the cavity 43a of the breathable mold 43 by gas suction in the direction, and after the molten metal 35 sucked by the breathable mold 43 is solidified. Together with the breathable mold 43, the casting chamber 4
2 is raised to take out the air-permeable mold 43, and a new air-permeable mold 43 is installed. Before and after this, the melting part chamber 33, the casting sleeve 41 and the casting part chamber 43 are installed. Slide on the surface plate 2 in the direction opposite to the arrow B direction to return to the original melting position, and repeat melting and casting.

Therefore, since the refractory crucible 32 is mounted inside the induction heating type cold crucible 31 which is relatively strong and has an induction heating capability, the refractory crucible 32 can be reinforced by the cold crucible 31. In addition, removal of the old refractory crucible 32 and installation of a new refractory crucible 32 can be significantly facilitated when a refractory crucible replacement is required.

Further, since the casting is carried out by vacuum suction, the hot water flow is good and it is possible to obtain a high quality precision cast product.

[0026]

The metal precision casting method according to the present invention is
A refractory crucible is mounted inside an induction heating cold crucible to melt a metal by induction heating, and the molten metal of the metal is suction-cast into a mold having air permeability. A precision metal casting device according to the present invention Since the induction heating type cold crucible has a melting part in which a refractory crucible is mounted, and a casting part for sucking and casting the molten metal of the metal melted in the melting part into a breathable mold. The refractory crucible mounted inside the induction heating cold crucible is reinforced by the induction heating cold crucible, preventing early damage, etc. and replacing the refractory crucible. When needed, the old refractory crucible was easily removed from the induction heated cold crucible, and again new refractory Since the attachment of the vowel is facilitated and the casting is carried out by vacuum suction, the molten metal of the molten metal can be kept in good condition and a high precision precision cast product can be obtained. It is possible to improve the quality of precision cast products.

[Brief description of drawings]

FIG. 1 is an explanatory view of essential parts of a metal precision casting apparatus used for carrying out a metal precision casting method according to the present invention.

FIG. 2 is an explanatory view in the horizontal direction of a water-cooled copper magnetic concentrator that constitutes an induction heating cold crucible. 1 Metal Precision Casting Equipment 3 Melting Section 4 Casting Section 31 Induction Heating Cold Crucible 32 Refractory Crucible 33 Melting Section Chamber 35 Metal Melt 41 Casting Section Sleeve 42 Casting Section Chamber 43 Breathable Mold 311 Water Cooled Copper Magnetic Concentration Body 312 induction heating coil

Claims (3)

[Claims] 1. A metal crucible characterized in that a refractory crucible is mounted inside an induction heating type cold crucible to melt a metal by induction heating, and the molten metal is suction-cast into a gas-permeable mold. Precision casting method. 2. An induction heating cold crucible having a melting part having a refractory crucible mounted therein, and a casting part for sucking and casting the molten metal melted in the melting part into a mold having air permeability. Precision casting equipment for metals. 3. The precision casting of a metal according to claim 2, wherein the refractory crucible is selected from oxides such as alumina, zirconia, magnesia, lime and yttria, and non-oxides such as boron nitride and graphite. apparatus.