JP2011230137A - Graphite crucible - Google Patents

Abstract

PROBLEM TO BE SOLVED: To remove restriction of casting aluminum that it is impracticable to leave a filter, which removes inclusions such as oxides in a molten metal to improve the quality of casting, at a running gate of a mold after pouring the metal into the mold, and to solve a problem that the filter should be preheated to prevent the temperature of the molten metal from being lowered by passing the molten metal through the filter.SOLUTION: The graphite crucible 10 includes: a body 1 which heats a block of stored aluminum in a melting furnace to melt the block and reserves the molten aluminum; and a lid 2, wherein an opening 4 for pouring the molten aluminum, positioned at the external periphery of a flange 2a arranged at the lid 2 and a filter 3 is arranged at the opening 4 to remove inclusions such as oxides by the filter 3.

Description

  The present invention relates to a graphite crucible for pouring a molten aluminum melt into a mold during a forged aluminum melt forging operation.

In the casting process to the mold of the molten metal forging molding operation, inclusions such as oxides potentially contained in the aluminum lump and an oxide film generated by contact with the atmosphere during conveyance of the molten metal are present in the molten aluminum. It is necessary to remove these inclusions before casting to ensure the quality of the molded product. Conventionally, a filter is provided in the pouring device. Also, this filter needs to be removed after pouring is completed. For example, a moving device for moving a ladle containing molten metal to a mold position, an elevating member for elevating the ladle and a tilting member for providing a tilting motion, and a tilting motion of the ladle provided on the elevating member or the tilting member. There has been disclosed a pouring device provided with a filter removing member that removes a filter inserted in a pouring gate portion of a mold in conjunction with the mold (for example, Patent Document 1).
As another example, a ladle having a slag outflow prevention lid on which an upper surface of a ceramic fiber molded body ladle body is fitted with a lid that substantially corresponds to the shape of the opening of the ladle body and projects many weirs downward is disclosed. (For example, Patent Document 2).

Japanese Utility Model Publication No. 04-003723 Japanese Utility Model Publication No.59-022923

However, the technique disclosed in Patent Document 1 requires a link mechanism as a filter removal member for removing the filter after pouring, which causes a high cost. In addition, when the molten metal passes through a filter having a temperature lower than the molten metal temperature, the molten metal temperature is lowered, which adversely affects casting quality.
The technique disclosed in Patent Document 2 is also configured such that the slag outflow prevention lid descends after the molten metal melted in the parent furnace is received by the main body, so that when the molten metal is injected into the mold, the molten metal is heated from the molten metal temperature. There is a problem that the temperature of the molten metal due to passing through the low-temperature slag outflow prevention lid is lowered, which adversely affects the casting quality.

  The present invention has been made to solve the above-described problems, and eliminates the cause of the temperature decrease of the molten aluminum melted in the casting process to the mold, and the graphite with a filter capable of removing oxides and the like. A crucible is provided.

  A graphite crucible according to the present invention is provided with a main body for storing a molten aluminum melt and a lid for the main body, while heating and melting the contained aluminum lump in a melting furnace. While the opening part for molten metal pouring is provided, the filter is provided in the opening part.

  Since the above construction is adopted, the graphite crucible and the filter are heated together with aluminum in the melting furnace, and before the casting to the mold, the molten aluminum for the work to move from the melting furnace to the ladle, etc. The factor of lowering the temperature of the molten metal is eliminated, and the molten aluminum can be prevented from lowering when the molten aluminum passes through the filter. In addition, the oxide film and inclusions in the melt can be filtered with a filter immediately before pouring into the mold, and the filter is installed in the graphite crucible, so the filter must be removed immediately before molding the mold. There is an excellent effect that there is no need to do.

FIG. 3 is a view showing a cross section, an upper surface and a side surface of the graphite crucible according to the first embodiment. It is a figure which shows the state at the time of the pouring to the metal mold | die by Embodiment 1. FIG. 6 is a view showing a cross section of a graphite crucible according to Embodiment 2. FIG. 6 is a view showing a cross section of a graphite crucible according to Embodiment 3. FIG.

Embodiment 1 FIG.
Embodiment 1 of the present invention will be described below with reference to the drawings.
1A is a view showing a cross section of the graphite crucible 10, FIG. 1B is a view as viewed from the arrow A, and FIG. 1C is a view as viewed from the arrow B when the opening 4 is viewed from the front. FIG. The graphite crucible 10 is constituted by a main body 1 having a bottomed cylindrical shape with a flange 1a provided on the upper portion thereof, and a substantially U-shaped lid 2 having a flange 2a on the flange 1a of the main body 1. An opening 4 for pouring molten aluminum is provided at one location in the circumferential direction of the flange 2a of the lid 2 in contact with the flange 1a of the main body 1, and the flange 1a of the main body 1 and the lid 2 are provided in the opening 4. The filter 3 fixed by the flange 2a is provided. The flange 1a is provided with a stepped portion 1b. The stepped portion 1b engages with a stepped engaging portion 2b provided on the lid 2 to prevent the lid 2 from sliding sideways with respect to the main body 1. is doing. The groove 2c provided on the back surface 2f of the lid 2 of the opening 4 of the lid 2 and the opening upper frame 2d forming the opening 4 constitute a locking portion 2e for locking the filter 3. This is because when the lid 2 is attached to the main body 1, the filter 3 is locked on the side of the lid 2, thereby preventing the filter 3 from being damaged and the workability of attaching the lid 2 to the main body 1. It is for improving.

  The filter 3 is a porous ceramic and has a substantially H-shaped cross section as shown in FIG. 1, and this H-shape is constituted by an outer wall 3a and an inner wall 3b connected to the backbone 3c. As shown in FIG. 1, the filter 3 is mounted such that the outer wall 3 a is outside the graphite crucible 10 and the inner wall 3 b is inside the crucible 10. As described above, the filter 3 is locked by the locking portion 2 e of the lid 2, and the lower surface of the trunk portion 3 c is engaged with the flange 1 a of the main body 1. The lower portion of the inner wall 3b of the filter 3 is provided with an inclined portion 3d that comes into contact with the inclined portion 1c provided on the flange 1a of the main body 1, and this makes it easy to attach the filter 3 to the main body 1. At the same time, the filter 3 is prevented from dropping from the graphite crucible 10 together with the locking portion 2e at the time of melting and heating the aluminum lump and transporting the molten metal. The filter 3 is a consumable part that can be removed from the lid 2. In the melting operation, an aluminum lump is inserted into the main body 1, a filter 3 is attached to the lid 2, set in the main body 1, and then inserted into a melting furnace (not shown). In this molten metal forging, a predetermined weight of aluminum is melted in a graphite crucible 10 with a high-frequency melting device for each cycle during casting, and the upper mold is poured into the lower mold of the molding press machine and filled with the press machine. Press molding is performed.

FIG. 2 shows a state of pouring into the mold by the graphite crucible 10 of the first embodiment. As can be seen from FIG. 2, not only the oxide in the molten metal but also the inclusions contained in the exfoliated pieces of the graphite crucible 10 and the aluminum lump through the porous filter 3 provided in the opening 4 of the graphite crucible 10. Is also filtered.
The porous ceramic according to the first embodiment is obtained by processing a ceramic plate provided with 20 holes (20 ppi) per inch to form a filter 3.
Such a filter 3 can remove inclusions in the order of several microns in the molten aluminum, contributes to improving the quality of the surface, inner surface, and processed portion of the aluminum product, and has the effect of improving the product yield. Moreover, since the aluminum lump is melted by the graphite crucible 10, there is no need to transfer from the main furnace to the ladle, the temperature of the molten metal can be prevented from being lowered, and the filter is heated at the same time as the molten metal and has the same temperature. Also, there is no drop in molten metal temperature due to the filter during pouring.
Although the filter 3 shown in FIG. 1 shows an example in which the inclined portion 3d is provided, depending on the size and capacity of the graphite crucible 10, it is not always necessary to provide the inclined portion 1c in the main body 1 or the inclined portion 3d in the filter 3. A simple H-shaped cross section may be used.

Embodiment 2. FIG.
In the second embodiment, as shown in FIG. 3, a metal mesh 5 coated with ceramic is used instead of the porous ceramic filter 3 of the first embodiment. The wire mesh 5 is provided so as to be locked to the locking portion 2e of the lid 2 and the flange 1a and the inclined portion 1c of the main body 1 described above. When such a wire mesh 5 is used, the filter can be configured with a high degree of freedom regardless of the shape of the opening 4.
The material of the wire mesh 5 is SUS304 and φ0.8 × 14 mesh is adopted. The reason for applying the ceramic coating is that it is installed in the graphite crucible 10 and exposed to a high temperature of 900 ° C. or higher in a melting furnace for about 30 minutes, and then the molten aluminum is passed through, preventing the wire mesh from being damaged or reacting with the wire mesh. It is to do.

Embodiment 3 FIG.
Next, Embodiment 3 will be described with reference to FIG. In the third embodiment, a projection 1d is provided on the flange 1a of the main body 1 corresponding to the opening 4 provided in the lid 2 described above. Then, instead of the filter 3 of the first embodiment, a porous ceramic filter 31 having a rectangular cross section as shown in FIG. 4 is provided. The filter 31 is held by the locking portion 2e of the lid 2 and the protrusion 1d. By employing the filter 31 having such a shape, the filter manufacturing cost is reduced.

1 body, 1a flange, 2 lid, 2a flange, 2e locking part,
3,31 filter, 4 openings, 5 wire mesh, 10 graphite crucible.

Claims (5)

A graphite crucible provided with a main body for storing and melting the molten aluminum melt in a melting furnace and a lid for the main body, and a lid provided on the lid. A graphite crucible characterized in that an opening for pouring is provided and a filter is provided in the opening. The main body is provided with a flange, and the cross-sectional shape of the filter is H-shaped, and the basic part of the filter is between the flange of the main body and the locking portion provided in the opening of the lid. The graphite crucible according to claim 1, wherein the graphite crucible is mounted so as to be locked. 3. The cross-sectional shape of the filter is rectangular, and the rectangular filter is held by a protrusion provided on the main body flange and a locking portion provided on an opening of the lid. A graphite crucible as described in 1. The graphite crucible according to any one of claims 1 to 3, wherein the filter is a porous ceramic. The graphite crucible according to claim 1, wherein the filter is a stainless steel wire mesh coated with ceramic.

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