JP3134578B2 - Vacuum melting furnace - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vacuum melting furnace for melting a metal in a vacuum vessel and pouring the metal into a mold to perform casting.

[0002]

2. Description of the Related Art A vacuum melting furnace of this type includes a crucible for melting a metal, a space for receiving a mold for receiving the molten metal in the crucible, and a molten metal in the mold positioned in the space for the mold. Heating means for applying heat, a solidification plate for placing the above-mentioned mold, and an elevating body for vertically moving the solidification plate, from the crucible to the mold located in the space While pouring the molten metal sequentially, the mold is sequentially lowered to perform casting. Such a vacuum melting furnace can perform very high quality casting.

[0003]

However, it is extremely troublesome to take a mold out of a vacuum vessel for taking out a casting, or to set a mold in a vacuum vessel for the next casting, and it takes a long time and a large amount of work. There was a problem that required great effort.

The present invention has been made to solve the above-mentioned problems (technical problems) of the prior art, and takes out a mold from a vacuum vessel for taking out a cast product, or removes a mold for the next casting. It is an object of the present invention to provide a vacuum melting furnace in which an operation of setting the inside of a vacuum vessel can be performed quickly and easily.

[0005]

In order to achieve the above object, a vacuum melting furnace according to the present invention has a space in which a crucible for melting metal and a mold for receiving a molten metal in the crucible are located in a vacuum vessel. And a heating means for applying heat to the molten metal in the mold positioned in the space for the mold, a solidifying plate for placing the above-described mold, and an elevating body for vertically moving the solidified plate. In a vacuum melting furnace in which the molten metal is sequentially poured from the crucible into the mold located in the space while the mold is sequentially lowered and cast, the detachment between the solidified plate and the elevating body is performed. On the side of the position where the coagulation plate is lowered while the free connection portion is interposed, the attachment / detachment operation of the connection portion and the in / out of the coagulation plate with the mold attached to a part of the side wall of the vacuum vessel. To form an opening with an open / close lid It is intended.

[0006]

The metal is melted in the crucible, and the resulting molten metal is poured into the mold, while casting is performed by gradually lowering the mold. When the mold is lowered, the opening / closing lid is opened, the connecting portion is operated from the opening to separate the solidified plate from the elevating body, and the mold is taken out of the vacuum vessel together with the solidified plate through the opening. When casting is performed again, another mold with a solidified plate is put into the vacuum vessel through the opening, and the solidified plate is connected to the elevating body by operating the connecting portion through the opening, and the next casting starts. it can.

[0007]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. In FIG. 1, reference numerals 1 to 23 denote constituent members of a well-known vacuum melting furnace, wherein 1 is a vacuum vessel, 2 is a melting place for melting metal, and 3 is a mold space for holding a mold. Reference numeral 4 denotes an exhaust port for evacuating the inside of the container 1, 5 denotes an inlet for charging a metal material into a crucible described later,
6 is a viewing window, 7 is a power supply port for supplying power to the induction coil in the container, 9 is a temperature measuring device for measuring the temperature of the molten metal in the crucible. Connected to Reference numeral 11 denotes a holder for holding the crucible 12 which is a metal melting container in the melting place 2, and includes a heating means for heating and melting the metal material in the crucible, for example, an induction coil. The holder 11 tilts the crucible 12 so that the molten metal therein can be poured out. Next, 14 is a heating means for applying heat to the molten metal in the mold located in the mold space 3, and a susceptor (for example, made of carbon) 15 surrounding the periphery of the space 3 and a susceptor 15 for heating the susceptor 15. And an induction coil 16 disposed therearound. Next, 19 is an elevating body in the elevating device 18 for moving the coagulation plate up and down,
Reference numeral 20 denotes a sealing device for sealing a portion where the elevating body 19 penetrates through the vacuum vessel 1, and reference numeral 21 denotes a solidification plate (also referred to as a chill plate) for mounting a mold 22, which is attached to the elevating body 19 and denoted by reference numeral 21a. It is possible to move up and down between a raised position shown and a lowered position shown by 21b. 23 is a guide member for guiding the pouring of molten metal.

Next, 24 is a connecting portion interposed between the elevating body 19 and the solidifying plate 21 for detachably connecting the latter to the former,
Reference numeral 25 denotes an opening provided in a part of the side wall 1a of the vacuum vessel 1 on the side of the lowering position of the solidification plate 21. The solidified plate 21 is formed in a size (width and height) capable of taking in and out of the solidified plate 21 and has an openable and closable lid.

Next, FIG. 2 showing in detail the elevating body 19, the solidification plate 21 and the connecting portion 24 thereof will be described. First, the elevating body 19 includes a water passage for circulating a refrigerant, for example, water with respect to the solidification plate 21. 26 is a waterway on the outward route, which is a cylindrical elevating body
It has 19 internal spaces. Reference numeral 27 denotes a cylindrical body for forming a water passage 28 on the return path side. Next, 29 is the connecting portion 24
A connecting part element on the side of the elevating body 19, which has a structure for mechanical connection and connection of a water passage. Reference numeral 30 denotes a connecting plate for mechanical connection and connection of the water passage on the outward path, which is formed in a flange shape and has a through hole 30a for inserting a connecting bolt. Reference numeral 31 denotes a water outlet on the outward path, and 31a denotes an O-ring for sealing. 32 is a member for connecting the return waterway,
An example of a joint connected to the cylindrical body 28 is shown, and the internal space is a water passage 33 on the return path side. 33a is an O-ring for sealing. Numeral 34 is a holding member for holding the joint 32 at the axial center position, and is formed with a plurality of through holes 34a for connecting the water passage 26 and the water inlet 31.

Next, the solidification plate 21 is formed in a disc shape and hollow so as to allow a refrigerant to pass therethrough. Reference numeral 35 denotes the water passage space. Reference numeral 36 denotes a mounting plate for mounting the mold, which is formed of a material having good thermal conductivity so that the mold can be cooled appropriately. 37 is the upper surface of the mounting plate 36 from the mold 22
This is a bank member for damping the molten metal leaking onto the top 36a, and is provided in an upwardly traveling state so as to surround the space on the upper surface 36a of the mounting plate 36. Next, reference numeral 38 denotes a water passage structure provided in the space 35 for cooling the solidified plate 21. 39 is a water passage on the outward path side, is constituted by a cylindrical body 40 provided in the center portion of the space 35 so that the flow of cooling water in the space 35 becomes uniform and a plate body 41 closing one end thereof,
The plate 41 has an outlet 42 through which cooling water flows out toward the central portion of the mounting plate 36 in order to cool the mounting plate 36 radially from the central portion thereof without bias. It is formed in. Reference numeral 43 denotes a water passage on the return path side, which is constituted by a through hole 44 formed in the cylindrical body 40, a cylindrical body 45 communicating with the through hole 44, and a cylindrical body 46 communicating with the through hole. Next, reference numeral 47 denotes a connecting portion element on the solidification plate 21 side of the connecting portion 24, which has a structure for mechanical connection and connection of a water passage. Reference numeral 48 denotes a flange-shaped connection plate for mechanical connection and connection of the water passage on the outward path, and has a plurality of through holes 48a for inserting connection bolts. 49 is a member for attaching the connecting plate 48 to the coagulating plate 21 with a space for attaching and detaching the connecting portion between them both,
A tubular body is used to form a water passage communicating with the water passage 39. Reference numeral 50 denotes a water passage on the outward path side of the connecting element 47, which communicates with the water passage 38 via the internal space of the cylindrical body 49. Reference numeral 51 denotes a connecting member of the water return passage on the return path in the connecting element 47, which is integrally formed with the cylindrical body 46, and has an internal space serving as a water return opening 52 on the return path side.

Next, casting by the vacuum melting furnace having the above configuration will be described. Outside the vacuum vessel, FIG.
As shown in (B), a mold 22 made of, for example, alumina is attached to the mounting plate 36 of the solidified plate 21 with alumina cement 53,
Heat to ~ 150 ° C to fix. Next, in a state where the elevating body 19 is at the lowered position, the solidified plate on which the mold 22 is attached
21 is inserted into the vacuum vessel 1 through the opening 25 and the connection element 47 is connected to the connection element 29. The connection between the two is performed by positioning the element 47 with respect to the element 29 so that the connection member 51 enters the inside of the joint 32 and the connection plate 48 overlaps with the connection plate 30, and bolts are inserted through the through holes 30a and 48a. Tighten the nut. Next, the elevating body 19 is raised to leave the mold 22 in the mold space 3. Next, the container 1 is evacuated as is well known,
The metal material charged in the crucible 12 is melted there. The mold 22 is heated by the heating means 14. Heating is induction coil
At 16, the susceptor 15 is heated and radiated heat from the susceptor 15 is used. When the metal material is melted and melted in the crucible 12, the crucible 12 is tilted and the melt is poured into the mold 22 sequentially. As is well known, the solidifying plate 21 is gradually lowered by the elevating body 19. Then, while the molten metal poured into the mold 22 is given heat by the heating means 14, it is cooled from below by the solidification plate 21, so that the molten metal is solidified sequentially from a lower position in the mold 22 upward. That is, unidirectional solidification is performed. Perform the above descending sequentially,
When the molten metal poured into the mold 22 solidifies and the solidified plate 21 reaches the lowered position 21b, the pressure inside the vacuum vessel 1 is restored and the opening 25 is opened.
The connecting portion 24 is cut off from the vacuum container 1 through the opening 25 and the coagulating plate 21 and the mold 22 are separated from each other.
Take out. Then, the operation of taking out the cast product from the mold 22 outside the vacuum vessel 1 is performed. When performing the casting operation continuously, the mold attached to another solidified plate may be charged into the container 1 in the same manner as above, and the same casting operation as above may be performed. In the casting by the above-mentioned one-way solidification, a very high-strength cast product can be obtained. Therefore, the casting is used, for example, for casting a turbine blade.

[0012]

As described above, according to the present invention, the molten metal is poured from the crucible 12 sequentially into the mold 22 located in the mold space 3 in the vacuum vessel 1, while the mold 22 is
Are successively lowered and casting is performed, so that there is an effect that it is possible to perform extremely high quality casting as generally known.

Moreover, after the casting is completed, the mold 22 is quickly taken out together with the solidification plate 21 from the opening 25 formed in a part of the side wall 1a of the container 1, and the mold 22 with another solidification plate 21 is exchanged for the elevating body 19. Also, there is an effect on work efficiency that the next casting operation can be started promptly after being mounted.

In addition, since the opening 25 is located beside the position where the solidified plate 21 is lowered, that is, the heating means 14 for applying heat to the molten metal in the mold 22 located in the mold space 3 is provided. Since it is the side of the depopulated space that does not need to be disposed, there is also an operational effect that the operation of attaching and detaching the coagulation plate 21 to and from the elevating body 19 through the opening 25 can be performed in a wide area.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view.

FIG. 2 is an exploded vertical sectional view showing details of an elevating body, a solidification plate, and a connecting portion.

FIG. 3A is a diagram schematically showing a relationship between a solidified plate and a mold,
(B) is sectional drawing which shows the attachment state of the casting_mold | template with respect to a solidification plate.

[Description of figure symbols]

 DESCRIPTION OF SYMBOLS 1 Vacuum container 3 Mold space 12 Crucible 14 Heating means 19 Lifting body 21 Solidification plate 22 Mold 24 Connecting part 25 Opening

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-63-290679 (JP, A) JP-A-1-170572 (JP, A) JP-A-4-305355 (JP, A) JP-A-58-1985 38656 (JP, A) Fully open 1988-111253 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) B22D 27/15 B22D 27/04 F27B 14/04

Claims (1)

(57) [Claims] 1. A crucible for melting metal in a vacuum vessel,
A space in which a mold for receiving the molten metal in the crucible is located, heating means for applying heat to the molten metal in the mold located in the space for the mold, a solidified plate for placing the above mold, and the solidified plate In the vacuum melting furnace is provided with an elevating body for vertically moving the molten metal from the crucible to the mold located in the space sequentially, while the mold is sequentially lowered and cast. A removable connecting portion is interposed between the solidification plate and the elevating body,
On the side of the position where the solidification plate is lowered, an opening and closing lid with an opening / closing lid is provided to allow a part of the side wall of the vacuum vessel to attach and detach the connection portion and to enter and exit the solidification plate with the mold. A vacuum melting furnace characterized by being formed.