JPH0723098Y2 - Rotating body for stirring and flowing molten metal - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention is directed to a molten metal for non-ferrous metal material such as aluminum or aluminum alloy that is stirred and flowed to float impurities on the surface of the molten metal and separate them. The present invention relates to a rotating body for stirring and flowing.

[Conventional technology]

Conventionally, when casting a casting made of non-ferrous metal material such as aluminum or aluminum alloy, in order to float and separate impurities in the molten metal and absorbed hydrogen,
Gases such as nitrogen, argon and chlorine are drawn into the molten metal,
Moreover, purifying means for bubbling and miniaturization are used. In this case, rotary bodies such as rotary vanes and rotary pumps are used. Since these rotary bodies are mostly made of sintered carbon, the consumption in molten metal or molten metal is extremely large. There is a drawback that. In order to solve such a defect, attempts have been made in recent years to form the rotating body with a ceramic material. However, as is well known, the ceramic material may be, for example, silicon carbide or silicon nitride. It has the drawback of being vulnerable to rapid thermal shock, and when the rotor is immersed in the molten metal, cracks occur, and in some cases the rotor is damaged or destroyed. In order to eliminate such an inconvenience caused by thermal shock, there is a proposal that the rotary body is provided with a lightening processed portion so that the maximum thickness is 30 mm or less (see Japanese Patent Laid-Open No. 63-104773).

[Problems to be solved by the device]

According to the above proposal, the temperature difference between the surface and the inside of the rotating body can be reduced and cracking due to thermal shock can be prevented. However, when manufacturing and using an actual rotating body, it is not always limited to thermal shock, and other problems also exist.

That is, as a result of providing the rotating body with a thinning processing part, not only the shape of the rotating body becomes a bowl-shaped body or an open cylindrical body, but also in the usage mode, the opening naturally faces downward. However, there is a problem that the gas that has passed through the rotary shaft stays in the lightening portion and is difficult to diffuse into the molten metal. In addition, when the gas staying in the lightening portion is intermittently discharged into the molten metal, it tends to become bubbles of relatively large size, and the impurities in the molten metal are floated and separated by refining the gas. There is also a problem in that the molten metal cleaning action cannot be performed completely.

The present invention solves the above-mentioned problems existing in the prior art, has not only high durability and long life, but also has a large stirring action of the molten metal and retains gas for purifying the molten metal. It is an object of the present invention to provide a rotating body for stirring and flowing molten metal, which has a structure capable of quickly diffusing in a molten metal.

[Means for Solving the Problems]

In order to achieve the above object, in the present invention, a rotating body for stirring and flowing molten metal, comprising a vertical rotating shaft having a hollow portion for supplying gas and a rotor fixed to the lower end of the rotating shaft, A circular concave portion which directly communicates with the lower end of the hollow portion of the rotary shaft is provided on the bottom surface of the rotor formed in the shape of a thin plate made of a nitride-based, boride-based, or carbide-based ceramic material. A technical means was adopted in which a plurality of radial grooves which communicate with each other and opened in the peripheral portion of the rotor were provided, and a plurality of concave grooves and / or protrusions were provided in the peripheral portion of the rotor.

In the present invention, the groove bottom of the radial groove may be formed horizontally. However, the groove bottom may be partially or entirely flat or curved so as to incline upward from the lower end of the hollow portion of the rotary shaft toward the peripheral edge. You may form in.

It should be noted that grooves and / or protrusions can be provided in the peripheral openings of the radial grooves.

[Action]

With the above configuration, since the rotor is first formed in a flat plate shape, it can be made relatively thin, and cracking due to thermal shock can be prevented. The gas supplied to the bottom surface of the rotor via the hollow part of the rotating shaft is continuously discharged into the molten metal from the opening of the rotor peripheral part through the radial groove provided on the rotor bottom part, and is also provided on the rotor peripheral part. The molten metal can be stirred by the plurality of concave grooves and / or protrusions. Therefore, the gas discharged into the molten metal is atomized by the molten metal flow and diffused into the molten metal, so that the molten metal cleaning action such as degassing and separation and floating of impurities can be effectively performed.

〔Example〕

1 and 2 are a longitudinal sectional view and a bottom view of an essential part showing an embodiment of the present invention. In both figures, 1 is a rotating shaft, which has a hollow portion 2 for supplying a gas such as nitrogen, argon, or chlorine, and is rotatably held in a vertical state. Reference numeral 3 denotes a rotor, which is formed in a thin plate shape and is fixed to the lower end portion of the rotating shaft 1 to form a rotating body. The rotor 3 is formed in a disk shape from a nitride-based ceramic material such as silicon nitride or sialon, a boride-based ceramic material such as titanium boride or zirconium boride, or a carbide-based ceramic material such as silicon carbide. A circular recess 4 is provided on the bottom surface of the rotor 3 so as to directly communicate with the lower end of the hollow portion 2 of the rotary shaft 1, and a radial groove 5 that communicates with this recess 4 and opens at the peripheral portion of the rotor 3 is provided. Set up. The recess 4
The bottom of the radial groove 5 is formed horizontally. Next, 6 is a groove, which is provided in plural numbers on the peripheral portion of the rotor 3.

When the rotary shaft 1 is connected to the drive device and the gas supply device (neither is shown) with the above-described configuration, the rotary shaft 1 is rotated and the gas for purifying the molten metal is introduced from the hollow portion 2, so that the rotor is rotated. If 3 is immersed in the molten metal, the molten metal can be purified. That is, the gas introduced from the hollow portion 2 is introduced into the concave portion 4 provided on the bottom surface of the rotor 3, but a thin gas layer (not shown) is formed by the action of the molten metal pressure or the liquid pressure. There is. Next, this gas layer is pushed by the subsequent supply gas, and the molten metal moves due to the centrifugal force due to the rotation of the rotor 3, so that the molten metal moves from the recesses 4 to the radial grooves 5 and is subdivided by the shearing action due to the rotation of the rotor 3. As a result, fine bubbles diffuse into the molten metal from the peripheral edge of the rotor 3. In this case, the gas is pressed against the bottom surface of the rotor 3 by the liquid pressure of the molten metal,
Since the bottoms (or ceilings) of the recesses 4 and the radial grooves 5 are formed horizontally, they can be easily moved to the peripheral edge of the rotor 3 without staying. On the other hand, since a plurality of concave grooves 6 are provided on the peripheral portion of the rotor 3, the molten metal can be stirred by the rotation of the rotor 3 and
The bubbles discharged from the radial groove 5 can be crushed. Therefore, the bubbles discharged from the rotor 3 are further miniaturized, and the diffusion action into the molten metal is promoted, and the purification action of the molten metal is further strengthened.

In the present embodiment, an example is described in which the recesses to be provided on the bottom surface of the rotor and the bottoms or ceilings of the radial grooves are formed horizontally. For example, as shown by a chain line a in FIG. You may form in a plane or a curved surface so that it may incline upward from the lower end of the hollow part of a rotating shaft toward a peripheral part. In the case of a curved surface, the curved surface is such that the inclination angle increases toward the peripheral portion. By forming as described above, it is possible to prevent the gas from staying in the radial groove and to make the movement of the gas toward the peripheral portion smoother. Furthermore, instead of the groove provided in the peripheral portion of the rotor or even if a projection is provided together with the groove, the molten metal and / or
Alternatively, the stirring and fluidizing action of bubbles is the same. Note that these concave grooves and / or protrusions may be provided in the peripheral opening of the radial groove.

[Effect of device]

Since the present invention has the structure and operation as described above,
It has extremely high durability and long life,
It has a great effect of stirring the molten metal, and because it can diffuse the gas for purifying the molten metal quickly into the molten metal without retaining it, it can degas the molten metal and float and separate the impurities efficiently and reliably. You can expect an effect.

[Brief description of drawings]

1 and 2 are a longitudinal sectional view and a bottom view of an essential part showing an embodiment of the present invention. 1: rotating shaft, 3: rotor, 5: radial groove, 6: concave groove.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A 2-115324 (JP, A) JP-A 63-104773 (JP, A) JP-B 61-40737 (JP, B2)

Claims (4)

[Scope of utility model registration request] 1. A rotary body for agitating and flowing molten metal, comprising a vertical rotary shaft having a hollow portion for supplying gas and a rotor fixed to the lower end of the rotary shaft. A circular recess that directly communicates with the lower end of the hollow portion of the rotating shaft is provided on the bottom surface of the rotor formed of a thin ceramic plate made of a carbide-based ceramic material, and communicates with this recess and opens at the rotor peripheral edge. And a plurality of concave grooves and / or protrusions are provided on the peripheral portion of the rotor, as well as a plurality of radial grooves. 2. The rotating body for stirring and flowing molten metal according to claim 1, wherein the bottom of the radial groove is formed horizontally. 3. The stirring of molten metal according to claim 1, wherein the radial groove is formed such that the groove bottom is partially or wholly inclined upward from the lower end of the hollow portion of the rotary shaft toward the peripheral edge. Flowing rotating body. 4. The rotating body for stirring and flowing molten metal according to claim 1, wherein the concave groove and / or the projection is provided at the peripheral opening of the radial groove.