JP2592549Y2 - Equipment for metal casting - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metal casting apparatus suitable for casting metals used in the field of dentistry, for example, refractory metals such as titanium.

[0002]

2. Description of the Related Art To date, prostheses have been used for restoring tooth decay or missing teeth, and materials constituting such dental prostheses include refractory metals such as titanium and zirconium. , Platinum and the like and alloys thereof are used. Among them, particularly titanium is a material which is very suitable in terms of strength, lightness, corrosion resistance, biocompatibility, price and the like, and is widely used. When a dental prosthesis is manufactured using such a metal, a mold in which a cavity of a desired shape is formed is used, and the above metal is melted in the cavity of the mold. In general, after casting by direct injection, the mold is broken and a casting is taken out.

[0003] As a general metal casting apparatus used so far, a tiltable metal crucible 2 is placed above a mold 3 having a casting cavity 9 as shown in FIG. Are arranged. This device is
The metal 4 placed on the upper surface of the crucible 2 is arc-melted in an inert gas (eg, argon gas) atmosphere. When the metal 4 is completely melted, the crucible 2 is tilted and the molten metal is poured into the casting port 5 of the mold 3. And casting is performed.
In this device, the crucible 2 moves so as to be tilted downward about the support shaft 6 (fulcrum), and stops at a position of 2 ″ via 2 ′. The electrode rod on the cathode side of the device of FIG. For 10, a general tungsten electrode rod is used.

However, in the metal casting apparatus shown in FIG. 4, since the support shaft 6 of the crucible 2 arranged above the mold 3 is located far from the casting port 5 of the mold 3, The crucible 2 and the mold 3 require a certain interval b 'required for tilting, and the crucible 2 when tilted is
To avoid contact with the molten metal,
It will fall a distance greater than b '. Generally, since the interval b 'is about 4 to 5 cm, there is a problem that it is difficult to drop the molten metal into the casting cavity 9 in the mold 3 at a high temperature with such an apparatus. In addition, there is a limitation in reducing the size of the casting apparatus.
In addition, in the case of the device having such a structure, the molten metal falls at a constant width a '(see FIG. 4), so that the molten metal adheres around the casting port 5,
There is also a problem that the metal drop position varies.

[0005] Separately, a metal 4 is placed on a crucible 2 having a hole as shown in FIG.
Generating an arc between 0 and metal 4 in an inert gas;
There is also an apparatus for performing casting by dropping a molten metal 4 ′ from a hole in the crucible 2 to a casting port 5 of the mold 3. Since the casting apparatus having such a structure does not have a movable structure, the distance b ″ between the crucible 2 and the mold 3 can be reduced as compared with the above-described apparatus, and the width a ″ at which the molten metal falls is also reduced. Crucible 2
Therefore, there is an advantage that the variation in the falling position of the metal is small. However, in the case of this apparatus, since the arc-melted metal drops naturally at the same time as melting, moderate overheating of the molten metal, which is indispensable for casting, is not realized at all. Therefore, similarly to the above-described apparatus, there is a problem that it is difficult to cast a high-temperature molten metal into the mold 3.

[0006]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems, and allows a metal melted at a high temperature to be cast into a mold without lowering the temperature. It is an object to provide a metal casting device having a stable structure. Another object of the present invention is to provide a metal casting apparatus having a structure in which molten metal can be cast using gas pressure instead of being cast into a mold by gravity drop.

[0007] The metal casting apparatus of the present invention is provided with a crucible and a mold inside a casting chamber capable of controlling the internal pressure, and the crucible applies the metal melted on the upper surface to the mold. In a metal casting apparatus having a structure that can be tilted about a support shaft so as to flow into a casting port,
It said support shaft, of the crucible, it is provided in the outlet end proximate to the casting port, the above crucible, means capable pulling the non-outflow end side is provided, and
The casting mold has a casting opening on a side wall thereof, and the casting
The crucible is arranged so as to be close to the mouth,
Moreover, the inside of the mold is obliquely downward from the casting port.
Casting diagonally upward through the stagnation part formed toward
A cavity is formed .

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings showing an example of an apparatus for metal casting of the present invention, but the present invention is not limited thereto. FIG. 1 is a diagram showing a state in which casting is performed using an example of the metal casting apparatus of the present invention. The structure inside the casting chamber 1 and the pressure required for controlling the internal pressure of the casting chamber 1 are shown. A state in which a vacuum pump 12, an inert gas (generally, argon gas) cylinder 13 and a three-way valve 14 are connected is shown. This vacuum pump 12
This is for exhausting the air inside the casting chamber 1. After the exhaust, the three-way valve 14 sends an inert gas from the inert gas cylinder 13 into the interior of the casting chamber 1.

In the apparatus according to the present invention, a crucible 2 and a mold 3 are provided inside the casting chamber 1. Above the crucible 2, a metal 4 placed on the crucible 2 is arc-melted. An electrode rod 10 is provided. This electrode rod 10
, A general tungsten electrode rod or the like is used, and the crucible 2 is a metal crucible. The crucible 2 has a structure that can be tilted about the support shaft 6 so that the metal 4 melted on the upper surface can be poured into the casting port 5 of the mold 3.

A major feature of the metal casting apparatus according to the present invention is that the support shaft 6 is provided at an outflow end (closer to the casting port 5) of the crucible 2 near the casting port 5,
In addition, the molten metal is cast into the mold 3 by raising the non-outflow end of the crucible 2 (that is, the side far from the casting port 5). Therefore, in the apparatus of the present invention, the position of the support shaft 6 supporting the crucible 2 is opposite to that of the conventionally used crucible tilting type casting apparatus. The movement when 2 is tilted is completely different. FIG. 1 shows a crucible 2.
Is shown by a dotted line when it is tilted about the support shaft 6 and reaches the position 2 '.

Further, the apparatus of the present invention is provided with a lifting means (lifting apparatus) 7 capable of lifting the non-outflow end side of the crucible 2 upward, and the structure of the lifting apparatus 7 is particularly limited. For example, the bottom surface of the crucible 2 on the non-outflow end side can be pushed up with a pin-shaped member, or a wire or the like can be attached to the non-outflow end side of the crucible 2 and pulled up. good. As a lifting device 7 having a particularly preferred structure, the lifting device 7 shown in FIG. 1 is exemplified. The lifting device 7 shown in FIG. 1 has the same structure as a seesaw, and has one end (the crucible 2). The weight 15 is attached to the other end of the crucible 2 so that the crucible 2 can be pulled up around the support shaft 6 at the other end. ing. Then, in a state before the metal 4 is melted, the lifting device 7 is held in a state in which the end on the crucible 2 side is lowered as shown by the solid line in FIG.
When the metal 4 is completely melted, the end on the side where the weight 15 is attached is lowered and reaches the position 7 'as shown by the dotted line. FIG. 6 shows an optimal positional relationship between the crucible 2 and the lifting device 7 in the present invention, and a structure in which the position of the weight 15 can be moved back and forth as appropriate so as to correspond to the weight of the metal to be melted. Is preferred. In the present invention, it is possible to manufacture castings of various sizes by such a structure.

In the present invention, a structure as shown in FIG.
That is, the mold 3 has a casting port 5 on the side wall side, and the crucible 2 is arranged so as to be close to the casting port 5, and inside the casting mold 3, obliquely downward from the casting port 5. A structure in which a casting cavity 9 is formed obliquely upward through the formed stagnation portion 8 is preferable, and a part of the crucible 2 is
It may have a structure in which the casting hole 5 is inserted. Such an apparatus is suitable for casting a metal or alloy having a high melting point, since casting can be performed in a state where the temperature of the molten metal does not decrease much. In the apparatus shown in FIG. 1, a slidable fixing member 11 is provided so as to be compatible with the molds 3 of various sizes.

The apparatus for metal casting of the present invention may have a structure in which the positions of the crucible 2 and the mold 3 are arranged in a vertical direction or a structure in which the positions of the crucible 2 and the mold 3 are arranged in a horizontal direction. When the mouth 5 is formed on the upper surface of the mold 3, the crucible 2 is disposed above the mold 3 as shown in FIG. On the other hand, when the casting port 5 is formed on the wall surface of the mold 3, the crucible 2 is arranged on the side of the mold 3 as shown in FIGS. 1 and 3. As can be seen by comparing FIGS. 2 and 4, in the case of the conventional apparatus (FIG. 4), a width a 'at which the molten metal falls and a distance b' at which the crucible 2 tilts are required. On the other hand, in the device of the present invention, the width a and the distance b only need to be as shown in FIG. 2, and these a and b are smaller than the aforementioned a 'and b'. As described above, the apparatus of the present invention has less variation in the falling position of the molten metal (a <a ′) and a smaller falling distance (b <
Since b ′), the temperature of the metal in the molten state does not easily decrease, and is suitable for producing a high-quality cast product.

The above-mentioned advantages are the same for the devices having the structures shown in FIGS. 1 and 3, but in the devices having these structures, the casting into the casting cavity 9 is caused by gravity drop. Is done without. That is, when the inside of the casting chamber is pressurized at the same time as the molten metal is poured into the retaining section 8 under reduced pressure, the molten metal is cast into the casting cavity 9 so as to be pushed up obliquely upward from the retaining section 8. In addition, metal casting using gas pressure can be performed. As can be seen by comparing the structure of the device shown in FIG. 2 with the structure of the device shown in FIGS. 1 and 3, in the case of the device shown in FIG. In the case of the apparatus having the structure shown in FIGS. 1 and 3, the casting cavity 9 is not affected by the gravity, while the apparatus having the structure shown in FIGS.
The molten metal does not enter, and the casting cavity 9 is instantaneously filled with the molten metal by the gas pressure. The cast product obtained by using such gas pressure is homogeneous, and is excellent in castability (fidelity of pattern).

In the metal casting apparatus according to the present invention, the crucible supporting table 1 having a shape as shown in FIGS.
6 may be used, and by appropriately changing the contact area with the bottom surface of the crucible 2, the heat capacity can be adjusted to an optimum heat capacity according to the type and volume of the molten metal.

[0016]

According to the metal casting apparatus of the present invention, a metal having a high melting point can be kept in a molten state when it is cast into a mold, and the molten metal can be poured into a predetermined position. As a result, high quality castings can be obtained. Further, the distance between the crucible and the mold can be reduced, so that the entire apparatus can be reduced in size.
Further, in the present invention, the mold and the crucible are arranged side by side and arranged side by side, and the casting port in the mold is provided on the side wall side, so that the pressure of gas is not used due to gravity drop. Casting can be achieved,
It is possible to obtain a product of higher quality than a cast product manufactured using a conventional apparatus. The device of the present invention has a structure in which the metal placed on the crucible is melted at a position close to the casting port of the mold, so that a high melting point metal such as titanium, which is particularly excellent as a dental prosthesis, is used. Suitable for casting.

[Brief description of the drawings]

FIG. 1 is a diagram showing a state when casting is performed using the metal casting apparatus of the present invention.

FIG. 2 is a diagram showing a positional relationship when a crucible 2 is provided on an upper surface side of a mold 3;

FIG. 3 is a diagram showing a positional relationship when a crucible 2 is provided on a side wall side of a mold 3;

FIG. 4 is a view showing a positional relationship between a mold 3 and a crucible 2 in a conventional casting apparatus of a type in which the crucible 2 is tilted.

FIG. 5 is a view showing a positional relationship between the mold 3 and the crucible 2 in a conventional casting apparatus of a type in which molten metal falls from a hole provided in the crucible 2.

FIG. 6 is a view showing an example of a means 7 for lifting the crucible 2 around the support shaft 6, and a state where the crucible 2 is inclined is indicated by a dotted line.

FIGS. 7A to 7C are diagrams showing shapes of a crucible support 16 for changing a heat capacity at the time of arc melting.

DESCRIPTION OF SYMBOLS 1 Casting room 2 Crucible 3 Mold 4 Metal 5 Casting port 6 Support shaft 7 Lifting means 8 Retaining portion 9 Casting cavity 10 Electrode rod 11 Fixing member 12 Vacuum pump 13 Inert gas cylinder 14 Three-way valve 15 Weight 16 Crucible support Table

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields surveyed (Int. Cl. ⁶ , DB name) B22D 45/00 B22D 21/06 B22D 23/00

Claims (1)

(57) [Scope of request for utility model registration] 1. A crucible 2 and a mold 3 are provided inside a casting chamber 1 capable of controlling an internal pressure, and the crucible 2 is provided with a metal 4 melted on an upper surface thereof.
A metal casting apparatus having a structure capable of tilting about a support shaft 6 so as to flow into the casting port 5 of the metal casting, wherein the support shaft 6 is an outflow end of the crucible 2 close to the casting port 5. That the crucible 2 has
Means 7 capable of lifting the non-outflow end side is provided , and the mold 3 has a casting port 5 on a side wall thereof,
The crucible 2 is arranged so as to be close to the entrance 5.
And the casting hole is provided inside the mold 3.
5 through the stagnation portion 8 formed diagonally downward,
An apparatus for casting metal , wherein a casting cavity 9 is formed diagonally above .