JPH06340937A - Forming method and device - Google Patents

Abstract

PURPOSE:To form a product of intricate shape or a high-density and large-sized product by supplying a forming material of a high-frequency inductive metal into a forming die, induction-heating and melting the material and lowering the die with respect to a heating coil. CONSTITUTION:A forming material 34 consisting of a high-frequency inductive metal is continuously or intermittently supplied into a forming die 10 consisting of a non-inductive material from the upper part, and the material 34 is induction-heated by an induction heating coil 26 placed outside the die 10 and melted. The die 10 is lowered with respect to the coil 26, and the molten material is solidified from its lower part. An inductive ceramic/metal composite material can be used as the material 34. The material is sufficiently degassed by this method in forming, the structure is homogenized, an unidirectionally solidified crystal structure is obtained, a product of intricate shape is formed, and a high-density and large-sized product is obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molding method and apparatus using high frequency induction heating.

[0002]

2. Description of the Related Art Conventional metal casting methods include casting,
Various types such as forging, machining, powder metallurgy are known. In the conventional casting method, the gas contained in the material to be cast, the gas generated in the casting process, the impurities on the surface of the mold, etc. remain inside the cast product to cause internal defects, the purity of the product decreases, and the surface Remains on the surface of the cast iron, which may cause deterioration of the casting surface. Therefore, there is a problem that the yield of the product is reduced. Further, there are problems that the structure of the material becomes non-uniform due to changes in the cooling conditions after casting the molten metal, and it becomes difficult to adjust the crystal structure such as unidirectionally solidified structure, single crystal structure and fine structure.

Forging and machining are difficult to form into complicated shapes, and the manufacturing cost is high. Further, powder metallurgy has a problem that it becomes a porous material and the density of the product becomes low.

On the other hand, it has been considered to use a composite material of metal and ceramics for the purpose of improving specific properties of a product. It is conventionally known to make this kind of material by sintering. That is, metal and ceramic powders are mixed, press-molded, and sintered. However, this method has a problem in that not only the material becomes porous and the density becomes low, but also complicated shapes and large shapes cannot be manufactured due to the convenience of press molding, and productivity is poor.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of such circumstances, and it is possible to sufficiently degas during molding and to adjust the crystal structure such as homogenization of structure and unidirectional solidification structure. An object of the present invention is to provide a metal forming method capable of forming a complicated shape and manufacturing a high-density and large-sized product at low cost.

At the same time, it is another object of the present invention to provide a method of molding a composite material which can efficiently produce a complex shape or a large size when a metal-ceramics composite material is used. Another object of the present invention is to provide a molding method capable of improving the purity of a product by preventing impurities from being easily mixed from the surface of the molding die. Yet another object is to provide a device which is used directly to carry out these methods.

[0007]

According to the present invention, the object is to supply a molding material made of a high frequency inductive metal or a ceramic composite metal material into the molding die continuously or intermittently from the outside of the molding die. It is achieved by a high-frequency heating and melting, and a molding method characterized by lowering this mold with respect to a high-frequency heating coil and solidifying from below.

Another object of the present invention is to provide a mold holding frame for holding a mold, a high-frequency heating coil provided outside the mold, and a high-frequency inductive granular molding material continuously or in the mold. The present invention is achieved by a molding apparatus including: a molding material supply unit that supplies intermittently; and a lifting drive unit that vertically moves the molding die holding frame relative to the high-frequency heating coil.

The mold can be made of a non-inductive material such as ceramics. The mold may be made of a metal such as copper, and in this case, it is desirable to divide it into a plurality of segments that are long in the magnetic field direction and to join each segment through an insulating material. Although it is desirable that the segments are electrically connected to each other, the molding material to be placed in the molding die itself may be brought into direct contact with the molding die to electrically connect the segments.

Further, the melting by the high frequency heating can be monitored by a temperature sensor or the like to control the descending speed of the molding die and the electric power of the high frequency heating coil. In this case, the molding die may be made of transparent quartz glass, and the state of the molding material inside may be visually observed from the outside, or the temperature may be detected from the outside with an infrared thermometer or the like to perform solidification analysis of the shape. A cooling unit may be provided below the high-frequency heating coil to rapidly solidify after melting and control the cooling rate.

Further, it is desirable to set an oxidizing atmosphere, an inert atmosphere, a reducing atmosphere, a vacuum atmosphere or a reduced pressure atmosphere depending on the material of the molding material. Further, HIP (Hot Isostatic Pressing process, Hot Isostatic Pressing) treatment can be performed in the molding process. The molding die can also be made by powder molding, and in this case, it is suitable for a consumable die or core which is disintegrated every time.

It is also possible to melt and solidify the molding material while vibrating the molding die by a vibrating device. In this case, the vibration device may be fixed to the molding die itself, or the vibration device may be fixed to a molding die holding frame that holds the molding die, and only the vibration may be transmitted to the molding die by a connecting rod or the like. Good. The frequency of vibration that excites the molding die is several tens to several hundreds.
However, ultrasonic waves of 20 KHz or higher may be used.

[0013]

The metal molding material supplied to the molding die is melted by high frequency heating in the lower part of the molding die, and degassing is performed during this period. Further, the molding material is continuously supplied while the molding die is descending relative to the coil. Therefore, the newly supplied molding material is melted by high frequency heating. Since a new molding material is sequentially supplied to the melting portion from above, the molding material does not solidify before melting. On the other hand, the part that has melted once and moved to the lower part of the coil solidifies in order. At this time, the metal structures are aligned in the same direction. The crystal structure can be adjusted by adjusting the moving mode of the coil and the cooling rate.

An eddy current due to an alternating magnetic field is induced in a portion melted by high-frequency heating (melting bath, pool of molten material), and an electromagnetic force (compressive force) toward the center is generated by the current and the magnetic field, so that the molten metal Are automatically stirred. At this time, an upward floating force acts on the molten metal at the same time, and a force in a direction away from the inner wall surface of the forming die acts on the periphery of the molten metal.
Therefore, the contact area between the molten metal and the inner wall of the mold is reduced,
Mixing of impurities from the inner wall of the mold is prevented. In particular, in the case where the mold is forcibly cooled with a cooling liquid, the molten metal which approaches or contacts the inner wall of the mold is rapidly solidified, so that the mixing of impurities is further reduced.

When a metal mold is used, it is desirable to divide the mold into segments that are long in the direction of the magnetic field and bond the segments to each other with an insulating layer in between. In this case, the eddy current induced in the mold is weakened, and the molding material in the mold can be efficiently heated. If the segments are electrically connected to each other, the potentials between the segments will be the same and there is no risk of arcing between the segments. Therefore, there is no possibility that the insulating layer is broken by the arc generation and impurities in the molding die are eluted into the molten metal.

When a part of the ceramic composite metal material is heated by high frequency heating, the metal powder is melted and the ceramic powder is dispersed in the molten metal. By mixing metal powder and ceramic powder homogeneously and continuously or intermittently supplying them, the ceramic powder can be homogeneously dispersed in the molten metal without being unilateral, and the region in this state is narrow. The ceramics can be uniformly dispersed in the entire product by moving them sequentially.

When vibration is applied to the molding die, the stirring action by the electromagnetic force accompanying the high frequency heating of the molten metal is smoothly performed. Therefore, the molten metal flows smoothly in the direction away from the inner wall surface of the molding die, the contact area with the inner wall of the molding die is further reduced, and the reaction with the molding die (mold reaction) is suppressed. As a result, mixing of impurities from the inner wall of the mold is reduced,
The purity of the product can be improved and the properties of the casting surface can be improved.

[0018]

1 is a side sectional view of an embodiment of the present invention, and FIG. 2 is a view showing a state in which the molding die is descending. In these drawings, reference numeral 10 is a molding die, which is made of a non-inductive material such as ceramics. As this material, zircon, fused silica, fused alumina, calcined clay, stucco particles such as mullite are attached to the disappearance model by a slurry containing a binder such as colloidal silica and ethyl silicate, and then the disappearance model is disappeared, It is possible to use a product that is further baked.

The mold 10 is placed on a mold support frame 12. The molding die support frame 12 can be moved up and down by a guide rail (not shown), and the height of the molding die support frame 12 can be increased or decreased by the elevation drive unit
Can be adjusted by. The ascending drive unit 14 moves the rack 16 and the molding die support frame 12 up and down by rotating the pinion 18 meshing with the rack 16 fixed to the outer surface of the molding die support frame 12 by an electric motor 20.

The molding die 10 is formed in a cylindrical shape, and a molding material supply pipe 22 is inserted into the molding die 10 from above. The supply pipe 22 is fixed to a base (not shown). A sensor 24, for example, an infrared temperature sensor, for detecting the temperature of the later-described melting portion A is attached to the lower portion of the supply pipe 22.

Reference numeral 26 is a high-frequency heating coil, 28 is a heat insulating plate mounted adjacent to the lower part of the coil, and 30 is a cooling section arranged below the heat insulating plate 28. Cooling unit 30
Cooling water is circulated in the mold, and the molding material heated and melted by the coil 26 is cooled and solidified. The coil 26, the heat insulating plate 28, and the cooling unit 30 are fixed to a base (not shown) like the supply pipe 22.

Reference numeral 32 denotes a control unit which controls the descending speed of the molding die support frame 12 or the electric power of the coil 26 by the elevation drive unit 14 based on the output of the sensor 24. Further, 36 is a vibrating device, which is fixed to the upper inner wall surface of the mold holding frame 12. Vibration is transmitted from the vibrating device 36 to the molding die 10 via the connecting rod 38. This vibration device 36
For example, the one that is vibrated at the same frequency as the commercial power source or a frequency that is an integral multiple thereof (about several tens to several hundreds Hz) can be used.

The vibrating device 36 may be one that generates a frequency other than the above, and an ultrasonic oscillator that generates an ultrasonic wave of about 20 KHz or higher may be used. The frequency to be used should be determined as an optimum frequency range depending on the size of the molding die 10, the type and volume of the molding material, and the like.

Needless to say, the mounting position of the vibrating device 36 is not limited to the embodiment shown in FIGS. For example, mold 1
0 may be added to the center or the lower part, or below the coil 26, and may be vibrated near the center of the molding die 10, the lower part or the coil 26, that is, if the molding die 10 is substantially vibrated. Good.

When using this apparatus, first, the molding die support frame 12 is raised as shown in FIG. 1 and set so that the bottom of the molding die 10 is near the coil 26. Then, the molding material 34 is supplied to the supply pipe 22 continuously or intermittently.

As the molding material 34, for example, iron,
Iron-based alloys (Ni, Co), copper, copper alloys, Cr alloys, S
A metal powder having fluidity such as stainless steel such as US304, 316, etc., particularly a sintering powder having a particle size of 0.7 to 1.0 mm is suitable. For example, a powder of a composite alloy in which 33 wt% of Tic is dispersed in SUS316 can be used.

As the ceramic composite metal material, for example, an iron-based base alloy is used as a mother alloy, and particles of ceramics (silicon carbide, silicon boride, silicon oxide, silicon nitride, etc.) are dispersed therein in an amount of 10 to 50 wt%. Can be used. In this case, it is desirable to perform melt casting in a vacuum or reduced pressure atmosphere, an oxidizing atmosphere, an inert atmosphere, or a reducing atmosphere according to the molding material 34. In particular, degassing can be promoted under a vacuum (reduced pressure) atmosphere.

The coil 26 is formed in a ring shape so as to surround the molding die 10 in a plane shape substantially orthogonal to the longitudinal direction of the molding die 10, and a high frequency current is supplied from a high frequency power source built in the control section 32. 450KHZ for stainless steel, for example
, 40 KW of power is applied to coil 26. Therefore, the molding material 34 located at the bottom of the coil 26 is heated and melted to form the melting portion A. The fusion zone A is heated to, for example, 1700 ° C.

If a new molding material 34 is supplied from the supply pipe 22 while moving the molding die 10 downward in FIG.
The newly supplied molding material 34 is piled up in a mountain shape on the fusion zone A to form the non-fusion zone B. Therefore, the non-melting portion B is heated by the coil 26 at high frequency, or is mixed into the melting portion A and melts, and is changed to the melting portion A. Mold 1
If a small amount of a piece or a lump of a metal plate is put in the bottom of 0 in advance, the melted portion A is first easily formed, and the subsequent processing becomes smoother.

During this time, the melting portion A is cooled from the lower portion to the cooling portion 3
It goes into 0 and is cooled and solidified. In FIG. 2, C shows this solidification part. As described above, while the molding material 34 is newly supplied, the molding die 10 is lowered and melted, and the molding is advanced while simultaneously solidifying the lower portion of the melting portion A,
It is possible to smoothly supply the molding material 34 to the melting portion A and obtain a high-quality molded product having no defects with a high yield.

Since the vibrating device 36 vibrates the molding die 10 here, the molten metal in the melting portion A flows smoothly. That is, since the molten metal to which the vibration is applied easily flows smoothly, the stirring action caused by the electromagnetic force of the magnetic field of the coil 26 in the molten portion A makes it possible to easily flow the molten metal. is there.

Therefore, the molten metal smoothly flows away from the inner wall of the forming die toward the center side, the time during which the molten metal is in contact with the inner wall of the forming die is shortened, and the reaction with the forming die is suppressed. As a result, less impurities are mixed into the product, the purity is improved, and the properties of the casting surface are improved.

FIG. 3 is a conceptual diagram of another embodiment. In this embodiment, HIP (Hot Isostatic Pressing process, Hot Isostatic Pressing) treatment is performed when high frequency heating and solidification are performed.

In this figure, reference numeral 50 is a pressure vessel main body, 52,
Reference numeral 54 denotes a lower lid and an upper lid, which are made of steel. A mold 58 is placed on a support 56 in the container 50, and a high frequency heating coil 60 is wound around the mold 58. The high frequency heating coil 60 is divided into a large number in the longitudinal direction of the molding die 58, and each portion can be independently energized.

62 is a feeder, and this feeder 62
The molding material 64 is accommodated in advance, and the amount of the molding material 64 supplied from the outside of the container body 50 into the molding die 58 can be controlled by the electromagnetic opening / closing valve 66.

The container body 50 is filled with a gas such as argon which serves as a pressure medium. Reference numeral 68 is a heat insulating material interposed between the coil 60 and the container body 50.

The inside of the container is 100 MPa (about 1000 kgf / cm
² ) The pressure is increased to the above pressure, the coil 60 is sequentially energized from the lower end side, the opening / closing valve 66 is opened / closed for a predetermined time accordingly, and the molding material 64 is supplied from the feeder 62 into the molding die 58. As a result, the molding material 64 is sequentially melted from the bottom side of the molding die 58 and then solidified, which is equivalent to moving the molding die 10 as shown in FIGS.

According to this embodiment, since the HIP process is performed under a high pressure, the density of the molded product can be increased, the structure can be densified, and the quality can be improved. This HIP treatment is preferably performed during high frequency induction heating and solidification,
The HIP treatment may be performed after the treatment by the high frequency induction heating.

For a molding die for a long product, the molding die may be placed at an angle and melted while the molding material is supplied from the lower side to the upper side, and the lower side may be solidified. However, it is desirable that the molding die is set up vertically as much as possible. In this case, gas and impurities are likely to rise along with the movement of the molten portion, and the effect of improving the purity of the product can be obtained.

The molding material supplied may be changed during the molding process. In this case, the material of the product can be changed partially or continuously. By supplying different molding materials from a plurality of feeders, for example, it is possible to change the material of the surface and the inside of the product, or to have the property as a functionally gradient material in which the material continuously changes.

Further, according to the present invention, the product can be improved in purity and the unidirectionally solidified structure can be further improved by repeating the high frequency heating a plurality of times by relatively reciprocating the coil after solidifying once. The molding dies 10 and 58 are not limited to those having a straight cylindrical shape as shown in FIGS. 1 and 3, but may be curved into an arc shape or have a complicated shape.

FIG. 4 is a perspective view showing another embodiment of the molding die,
FIG. 5 is a sectional view showing a usage state. The mold 70 is made of metal such as copper. That is, it is formed in a cylindrical shape with the lower part closed and the upper part opened, except for the bottom part 72 thereof.
4 has slits formed in its longitudinal direction to form vertically long segments 76. An insulating layer 78 is loaded in each slit. As a result, each segment 76 is electrically connected at the bottom 72.

A cooling liquid passage 80 is formed in each segment 76 as shown in FIG. 5, and a pipe 82 is introduced into each cooling liquid passage 80. The pipes 82 are assembled in the bottom 72. The cooling liquid is supplied to each pipe 82 from this collecting portion 84, and the cooling liquid jetted from the upper end of each pipe 82 cools the inner wall of the cooling liquid passage 80 and the bottom portion 72.
It is discharged from a discharge port 86 provided in the.

As shown in FIG. 5, the molding die 70 is relatively lowered in the high frequency induction coil 88, and at this time, the molding material 94 is continuously or intermittently fed from the feeder 90 through the electromagnetic opening / closing valve 92. 70 is supplied. Molding material 94
Is melted by high-frequency heating, while solidifying portion C below it
Is in contact with the mold 70. An electromagnetic force due to the magnetic field of the coil 88 acts on the fusion zone A or the non-fusion zone B, and
It is agitated as indicated by the arrow. The non-melting portion B is a state in which the non-melting molding material 94 is mixed in the molten metal.

Further, a molding die 70 is provided on the periphery of the fusion zone A.
The levitation force acts in the direction away from the inner wall of the.
Therefore, the peripheral edge of the melting portion A hardly contacts the inner wall of the molding die 70, and even if it contacts, the contacted portion immediately solidifies. Therefore, the impurities of the mold 70 are hardly eluted into the molten metal.

Particularly, when the forming die 70 is vibrated by a vibrating device (not shown), the flow of the molten metal becomes smoother as described above. Therefore, the peripheral edge of the melted portion A is less likely to contact the inner wall of the molding die 70, and the elution of impurities into the product can be further prevented.

According to this embodiment, the impurities of the molding die are less likely to be eluted into the molten metal, so that the purity of the product can be further improved. For example titanium, zirconium, hafnium,
It is possible to mold metals such as molybdenium, chromium, niobium and alloys thereof with high purity. In order to improve the mold separation between the mold 70 and the solidified product and to prevent the elution of impurities more reliably, the mold 7
The inner wall of 0 may be coated with boron nitride or the like.

FIG. 6 is a view showing still another embodiment of the molding die. The molding die 100 includes a copper plate 102 and an insulating material 10.
4 and a large number of blocks 106 alternately stacked (see FIG. 6).
(A) is prepared and the recess 108 is formed in this block 106 by machining. As the insulating material 104 used here, for example, glass fibers may be impregnated with a resin and adhered between the copper plates 102 and cured. It is desirable that the mold 100 be cooled by processing a cooling liquid passage or the like, but it may be cooled by applying a cooling liquid to the outside.

According to this mold 100, the block 10
By preparing 6 in advance, it is possible to easily deal with the manufacture of products having various shapes, and it is easy to reduce the manufacturing cost and the manufacturing period of the molding die 100. This molding die 100
However, no electrical connection is made between the copper plates 102.
However, if the molding material is supplied into the recess 108 and melted and solidified, electrical connection between the copper plates 102 becomes possible via the molding material itself.

In each of the embodiments described above, the molding material 34,
Although 64 and 94 are granular or powdery, the present invention is not limited to this. For example, molding material is wire, rod
It is possible to have various shapes such as a plate shape, a plate shape, and a block shape. In short, any shape may be used as long as the molding material can be continuously or intermittently supplied into the molding die. The wire or thin plate may be a long continuous molding material.

The mold used in the present invention can also be made by powder molding. That is, according to the present invention,
Gravity and heat shock applied to the molding die are mainly applied to the melting portion of the molding material, and other portions are extremely small, so that a powder molded product having low strength can be used. The powder used here is preferably a non-inductive powder such as ceramic powder.

As a molding die for this powder molding, it is possible to significantly reduce the cost by using it as a mold which is disintegrated once, for example, a consumable mold or a core. The consumable mold and the core can be hardened by supplying a powder material to a mold such as a mold and heating and pressing. In this case, no sintering is necessary, and the powder material has an intermolecular force (van der Waals force).
Also, they are bound by the capillary force and electrostatic force of water.

The mold may be subjected to various gas curing methods or the like in order to further increase its strength. For example, in the case of using foundry sand with sodium silicate as a binder, the hardening can be promoted by blowing carbon dioxide gas (C
O ₂ process). When an ethyl silicate binder is used, the curing can be promoted by ammonia gas.

The mold used for powder molding may be a normal non-hollow mold, but it may be hollow or may have a core inside (core mold). In the case of a hollow core, for example, a bag of elastic film is held in a split outer mold, and a powder material is put between this bag and the outer mold, and then high-pressure gas is supplied to this bag, It is possible to inflate and press the powder agent with the outer mold by this bag to mold it.

This method is applied to Japanese Patent Application No. 2-1 by the same applicant.
Since it is described in detail in JP-A-44381 (Japanese Patent Application Laid-Open No. 4-37437), no further explanation will be given here, but it is desirable to make the wall thickness as thin as possible in order to improve the disintegration property of the core after casting.

Molding die having a core by powder molding (core type)
When making, it is possible to combine with a mold. FIG. 7 is a cross-sectional view of such an embodiment. In this figure, 120 is a molding die, and a core 124 of a core is integrally formed inside the main die 122.

In order to improve the efficiency of high frequency heating, the main mold 122 is provided with slits to sandwich an insulating material,
It is desirable to have a structure in which metal plates and insulating materials are alternately laminated. The portion of the core 124 does not necessarily have to have the same structure as the portion of the main mold 122, but preferably has the same structure. Cooling liquid passages 126 and 128 that branch into a main mold 122 and a core 124 are formed in the wall thickness of the molding die 120.

Pipes 130 and 132 are introduced into the cooling liquid passages 126 and 128, respectively. These pipes 130,
132 is collected at the bottom, and the cooling liquid is supplied to the pipes 130 and 132 from the collecting portion 134. Each pipe 13
The cooling liquid ejected from the upper end of
6,128 outlet 136 provided at the bottom while cooling the inner wall
Emitted from.

A core 138 is formed on the central core 124 by powder molding. That is, the core 124 of this mold
Can be set in the outer mold of the core 138 and powder-molded. If this molding die 120 is used, the core 138 can also be cooled and solidification management can be performed with higher accuracy. It is needless to say that the above-mentioned effects can be obtained by vibrating the molding die also in the embodiments of FIGS. 3 to 7
In the embodiment, it is needless to say that the effect as described above can be obtained by vibrating the molding die.

[0060]

As described above, the invention according to claim 1 or 2 is such that a molding material such as a high frequency induction metal or a ceramic composite metal material is continuously or intermittently supplied into the molding die. Since the molding material is melted while moving the melting part from the bottom to the top by high-frequency heating from outside, and then solidified, by controlling the movement of the molding die or the coil and the supply amount of the molding material, It is possible to smoothly mold while moving the melting portion upward. Therefore, the molding material is always solidly supplied without solidifying above the melting portion.

Further, the process of melting and solidifying at the time of molding can be controlled by the current of the coil, the mold or the ascending / descending speed of the coil, and degassing or control of the structure, for example, unidirectional structure, single crystal structure, fine structure. It becomes possible to control the crystal structure such as. For this reason, it is possible to supply a product having a complicated shape with sufficient strength which is not inferior to forging and machining at low cost.

The mold may be made of a non-inductive material such as ceramic (claim 3), or may be made of metal such as pure copper. When the mold is made of metal, it is desirable to divide it into a plurality of segments at the dividing surface in the magnetic field direction (claim 4). In this way, the eddy current generated in the molding die can be weakened and the molding material can be efficiently heated.

Further, if each segment is electrically connected, arc discharge does not occur between each segment, dielectric breakdown between the segments due to arc discharge, elution of impurities on the surface of the molding die, and the molding die itself. Can prevent destruction. The electrical connection between the segments may be made by the molding material itself that is placed in the molding die.

In particular, when the metal powder and the ceramic powder are mixed and continuously or intermittently supplied, the molding material is gradually melted little by little, so that the ceramic powder is homogeneously mixed in the molten metal. Therefore, a product made of a ceramic composite metal material having desired properties can be efficiently manufactured. Further, since it is not necessary to press-form the powder, it is suitable for producing a large-sized product (claims 2 and 6).

The molding material may be a powder for sintering metal, or a powder material for sintering metal and ceramic powder (claims 5 and 6). The molding material is granular, powdery, linear, rod-shaped,
It may have various shapes such as a plate shape and a block shape (claim 7). It should be noted that it is desirable to use either an acidic atmosphere, an inert atmosphere, a reducing atmosphere, a vacuum atmosphere, a reduced pressure atmosphere, or the like depending on the type of molding material used (claim 8).

Further, by repeating high frequency heating a plurality of times, the accuracy of the product can be further improved. If the mold and the molding material are subjected to the HIP treatment during the high frequency heating and the solidification, the product density is further increased and a high quality product without defects can be obtained.

If vibration is applied to the molding die, the flow of the molten metal in the melting portion becomes smoother. The electromagnetic force generated by the high-frequency coil causes a flow in the molten metal at this melting point,
At this time, the molten metal is in a state of easily flowing by vibrating, so that the molten metal flows smoothly.

Therefore, as soon as the molding material melts, it flows from the inner wall of the molding die toward the center, and even if it contacts the inner wall of the molding die, the time is shortened. As a result, the reaction between the molten metal and the inner wall of the mold is suppressed, and the elution of impurities into the product is reduced,
It is possible to improve not only the product purity but also the casting surface (claim 9).

According to the inventions of claims 10 to 19, a metal forming apparatus directly used for carrying out this forming method can be obtained. If the mold is made of transparent quartz glass, the internal condition can be directly monitored from the outside (claim 14). For example, the process of melting and solidification can be monitored by an infrared thermometer, and the analysis data of the solidification process can be easily obtained. Further, the molding die may be made by powder molding, and in this case, it becomes possible to efficiently make the consumable die and the core at low cost.

[Brief description of drawings]

FIG. 1 is a side sectional view of an embodiment of the present invention.

FIG. 2 is a view showing a state in which the forming die is descending.

FIG. 3 is a conceptual diagram of another embodiment.

FIG. 4 is a perspective view showing another embodiment of the mold.

FIG. 5 is a view showing a usage state of this mold.

FIG. 6 is a view showing another embodiment of the molding die.

FIG. 7 is a view showing another embodiment of the molding die.

[Explanation of symbols]

 10, 58, 70, 100, 120 Forming die 12 Forming die holding frame 14 Elevating drive part 22 Supply pipe as forming material supply part 24 Sensors 26, 60, 88 High frequency induction coil 30 Cooling part 32 Control part 34, 64, 94 Cast material 36 Vibrating device 62, 90 Feeder as molding material supply section A Melting section B Non-melting section C Solidification section

Claims (19)

[Claims] 1. A high-frequency heating coil in which a molding material made of a high-frequency inductive metal is continuously or intermittently supplied into the molding die from above and the supplied molding material is provided outside the molding die. The molding method is characterized in that it is melted by high-frequency heating by means of, and the mold is lowered relative to the high-frequency heating coil to solidify from below. 2. High-frequency heating in which a molding material made of a high-frequency inductive ceramics composite metal is continuously or intermittently supplied from above into the molding and the supplied molding material is provided outside the molding die. A molding method characterized in that a coil is high-frequency heated and melted, and the mold is lowered relative to the high-frequency heating coil to solidify from below. 3. The molding method according to claim 1, wherein the mold is made of a non-inductive material. 4. The molding method according to claim 1, wherein the molding die is formed of a plurality of metal segments joined to each other through an insulating layer. 5. The molding method according to claim 1, wherein the molding material is a powder material for sintering iron or stainless steel. 6. The molding method according to claim 2, wherein the molding material is a sintering material in which ceramic powder is mixed with metal powder. 7. The molding method according to claim 1, wherein the molding material has any of a granular shape, a powder shape, a linear shape, a rod shape, a plate shape, and a block shape. 8. The molding material is an acidic atmosphere, an inert atmosphere,
3. The molding method according to claim 1, wherein the molding die is supplied under a reducing atmosphere, a vacuum atmosphere, or a reduced pressure atmosphere. 9. The molding method according to claim 1, wherein the molding die is subjected to high frequency heating while being vibrated. 10. A molding die holding frame for holding a molding die, a high-frequency heating coil provided outside the molding die, and a molding for supplying a high-frequency inductive molding material into the molding die continuously or intermittently. A molding apparatus comprising: a material supply unit; and a lifting drive unit that vertically moves the molding die holding frame relative to the high-frequency heating coil. 11. The sensor according to claim 10, which detects that the molding material in the molding die has melted, and the descending speed of the molding die holding frame by the elevating and lowering drive unit and the high-frequency heating coil based on the output of this sensor. And a control unit for controlling at least one of the exciting power of the molding machine. 12. The molding apparatus according to claim 9, further comprising a cooling unit below the high-frequency heating coil for cooling the molding die. 13. The molding apparatus of claim 10, wherein the mold is made of a non-inductive material. 14. The molding apparatus according to claim 13, wherein the molding die is made of transparent quartz glass, and the state of supply, melting, and solidification of the molding material in the molding die can be monitored from the outside. 15. The molding apparatus according to claim 10, wherein the molding die is made by powder molding. 16. The metal forming apparatus according to claim 10, wherein the forming die is formed by joining a plurality of metal segments, which are long in the magnetic field direction formed by the high frequency heating coil, to each other through an insulating layer. 17. The molding apparatus according to claim 16, wherein a cooling liquid passage is formed in each of the segments, and the cooling liquid is circulated in the cooling liquid passage. 18. The molding apparatus according to claim 10, wherein the molding die is made by machining a block in which a large number of metal plates and an insulating material are laminated. 19. The molding apparatus according to claim 10, further comprising a vibration device that vibrates the molding die.