JP4239604B2 - Molten metal casting equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a molten metal casting apparatus, and more particularly to a technique for removing impurities or unnecessary substances contained in a molten metal.
[0002]
[Prior art]
Conventionally, in a casting apparatus for supplying molten metal (molten metal) such as aluminum and guiding it to a casting part to cast a vehicle wheel or the like, impurities contained in the molten metal, for example, oxides such as aluminum, enter the casting part. In order to prevent this, a technique for removing impurities by providing a filter in a molten metal passage is known. The filter is formed by, for example, forming a large number of holes in a flat plate or combining fine lines in a mesh shape.
[0003]
[Patent Document 1]
Japanese Utility Model Publication No. 59-68659 [0004]
[Problems to be solved by the invention]
The hole diameter of the filter or the diameter of the mesh-shaped opening is defined according to the size of the impurities to be removed, and it is preferable that the diameter is as small as possible from the viewpoint of removal performance. However, if the diameter is reduced, the flow resistance of the molten metal increases, so the casting efficiency decreases. Further, impurities adhere to the filter and block the hole or opening, and the flow resistance of the molten metal increases similarly.
[0005]
It is an object of the present invention to provide an apparatus capable of reducing impurities contained in a molten metal by reducing the diameter of a filter and suppressing a decrease in casting efficiency.
[0006]
[Means for Solving the Problems]
The present invention relates to a molten metal casting apparatus including a casting part and a passage for supplying molten metal to the casting part, the filter means provided in a part of the passage, and the filter means at high speed Drive means for vibrating. Impurities contained in the molten metal are removed by providing the filter means in the passage, and the filter means is vibrated at high speed by the driving means, whereby the impurities adhering to the filter means are crushed to suppress an increase in the flow resistance of the molten metal. Moreover, by letting the filter means vibrate at high speed, the wettability with the molten metal is improved, and the passage of the molten metal can be facilitated even if the diameter of the filter means is reduced.
[0007]
For example, it is preferable that the driving unit ultrasonically drives the filter unit.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0009]
FIG. 1 shows the configuration of a casting apparatus according to this embodiment. Molten metal is supplied from a hot water container that contains molten metal such as molten aluminum, and is supplied to the casting part 12 through the passage 10. The casting part 12 is provided with a mold, and an aluminum wheel or the like of the vehicle is cast by pouring the molten metal into the mold.
[0010]
At least a part of the passage 10 is provided with a filter 14 to remove impurities (for example, aluminum oxide) contained in the molten metal. The filter 14 is made of a material that is not affected by a molten metal material such as spongy cordierite, high alumina, silicon nitride, silicon carbide, or graphite. The filter 14 can also be configured by forming a large number of holes in these materials, and can also be configured by combining fine wires of these materials in a mesh shape.
[0011]
Conventionally, the hole diameter of the filter 14 is set to, for example, about 2 mm in consideration of the flow resistance of the molten metal. In this embodiment, the diameter of the hole is set to, for example, about 5 μm. That is, the conventional mm order is reduced to the μm order. Thereby, the impurity contained in a molten metal can be removed reliably.
[0012]
On the other hand, the filter 14 is provided with a drive unit 16 for causing the filter 14 to vibrate at high speed. The drive unit 16 includes an ultrasonic driver, and vibrates the filter 14 at a high speed with an ultrasonic frequency (20,000 Hz or more). By vibrating the filter 14 at high speed, even if impurities of the molten metal adhere to the filter 14, it can be crushed, and an increase in flow resistance due to the adhesion of impurities can be suppressed to maintain casting efficiency.
[0013]
FIG. 2 schematically shows a state where the filter 14 is ultrasonically driven. 2A shows a comparison between the hole diameter of the filter 14 of the embodiment and the diameter of the hole of the conventional filter, and FIG. 2B shows the filter 14 of the embodiment and the conventional filter. The state of impurity removal in the filter is shown. Since the hole diameter of the filter 14 of the present embodiment is set to several μm, impurities of a size that could not be removed conventionally can be removed reliably, and the quality of the cast aluminum wheel or the like is improved. Moreover, since the filter 14 of the present embodiment vibrates at high speed, the adhering impurities are crushed, and the conventional filter clogging can be suppressed. The crushed impurities pass through the filter 14 and reach the casting part 12, but since they are crushed sufficiently small, the quality of the cast product is hardly affected.
[0014]
Further, since the surface of the filter 14 is oxidized to form a thin oxide film, the wettability with the molten metal is generally low, and the flow resistance to the molten metal increases when the diameter of the filter 14 is reduced. However, by ultrasonically vibrating the filter 14, the surface oxide film of the filter 14 is removed to some extent, thereby improving the wettability with the molten metal and reducing the flow resistance even if the diameter of the filter 14 is reduced to about several μm. Can be reduced.
[0015]
In this embodiment, the filter 14 is vibrated at high speed by ultrasonic driving. However, the filter 14 may be vibrated at high speed using another method, for example, a piezoelectric element. In the present embodiment, the filter 14 is constantly vibrated at high speed, but may be periodically vibrated at a predetermined interval.
[0016]
Furthermore, in the present embodiment, only one filter 14 is provided at a predetermined location of the passage 10, but a plurality of filters 14 may be provided at different positions in the passage 10 and each filter 14 may be vibrated at high speed. In this case, the diameters of the holes of the plurality of filters 14 and the frequency of the high-speed vibration may be the same or may be changed from each other.
[0017]
【The invention's effect】
As described above, according to the present invention, it is possible to remove impurities contained in the molten metal, and to suppress a decrease in casting efficiency and to perform high-quality and high-efficiency casting.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of a casting apparatus according to an embodiment.
FIG. 2 is a functional explanatory diagram of a casting apparatus according to an embodiment.
[Explanation of symbols]
10 passages, 12 casting parts, 14 filters, 16 driving parts.

Claims (1)

A casting part;
A passage for supplying a molten aluminum melt to the casting part;
A molten metal casting apparatus comprising:
A filter means provided in a part of the passage and having a hole diameter on the order of several μm ;
Drive means for ultrasonically vibrating the filter means;
An apparatus for casting molten metal, comprising:

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