JPH1029037A - Forging method and forging device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a formed product restrained with blow hole and recessed part developed from a shrinkage cavity by forming a product forming part and a non- product forming part in a molding flask and making temp. cooling gradient gentle at the time of solidifying molten metal in the product forming part. SOLUTION: Molten aluminum is poured to each of casting ranges 12, 13 from a feeder head 11 so as to fill them and further, fill up the feeder head 11. The molten aluminum starts to solidify from a first casting range 12. In such a case, the temp. cooling gradient of the molten aluminum in the whole casting range is made more gentle compared with the case of using only the first casting range 12 because of the existence of the molten metal in the second casting range 13 and the molten metal in the feeder head 11. Therefore, it is not developed that the thin thickness part is finally solidified. By this method, in the first casting range 12, the molten aluminum is gradually solidified and further, in the part of shortage of the molten metal, the molten aluminum is solidified while supplying the molten aluminum. Therefore, in an aluminum casting turning-over metallic mold cast in the first casting range 12, the blow hole and the recessed part developed from the shrinkage cavity, are not developed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a casting method.

[0002]

2. Description of the Related Art FIG. 5 is a sectional view of a casting frame for producing a conventional aluminum casting reverse mold. In FIG. 5, a casting mold 20 made of ceramic is set in an iron casting frame 20 to produce an aluminum casting reverse mold. Then, aluminum is turned into the casting frame 20 in which the mold 21 is set and solidified to form the aluminum casting reverse mold 22.

[0003]

The aluminum casting reversal mold 22 formed as described above has a thin center portion and a thick outer portion. As a result, the completed aluminum casting reversal mold 22 had burrows and dents in the thin center portion.
This is because when aluminum solidifies, solidification starts from the part in contact with the casting frame and finally solidifies in the central part, so the shortage of molten metal due to solidification shrinkage causes shrinkage cavities to concentrate in the central part and further spread to the outer peripheral part This is because it occurs.

[0004] If the aluminum casting reversal mold 22 has a cavity, there is a problem in improving the quality of a product at the time of injection molding using the mold 22. Further, when a recess occurs in the aluminum casting reversal mold 22 to be formed, an operation for filling the hole of the recess must be performed.

The present invention has been made in order to solve the above-mentioned problems, and an object of the present invention is to provide a casting method capable of producing a molded article in which burrows and dents caused by shrinkage cavities are suppressed. And a casting apparatus.

[0006]

In order to solve the above-mentioned problems, a first aspect of the present invention is to form a molded product portion and a non-molded product portion in a casting frame, and to flow a molten metal into the casting frame. The gist of the present invention is a casting method in which a temperature cooling gradient when the molten metal in the molded product part solidifies is moderated.

According to a second aspect of the present invention, a molded product part and a non-molded product part are formed in a casting frame, and a feeder lid having a pouring opening communicating with the non-molded product part is provided above the casting frame. Pour molten metal from the spout of the riser lid over the height of the casting frame to reduce the temperature cooling gradient when the molten metal in the molded product part solidifies, and to solidify the molded product part during solidification. The gist is a casting method for replenishing a shortage of molten metal due to shrinkage.

The gist of the invention according to claim 3 is a gist of a casting apparatus in which a molded product part and a non-molded product part are formed in a casting frame. According to a fourth aspect of the present invention, there is provided a casting apparatus in which a molded product portion and a non-molded product portion are formed in a casting frame, and a feeder lid having a spout communicating with the non-molded product portion is provided at an upper portion of the casting frame. The device is the gist.

Therefore, according to the first aspect of the present invention,
The temperature cooling gradient when the molten metal in the molded product part solidifies is reduced. According to the invention described in claim 2, the temperature cooling gradient when the molten metal in the molded product part solidifies is reduced,
The lack of molten metal due to solidification shrinkage during solidification of the molded product part is supplemented by the weight of the molten metal in the spout of the riser lid.

According to the third aspect of the present invention, when the molten metal flows into the casting frame, the temperature cooling gradient when the molten metal in the molded product portion solidifies is reduced. According to the invention as set forth in claim 4, when the molten metal is poured from the spout of the riser lid to a height equal to or higher than the height of the casting frame, the temperature cooling gradient when the molten metal in the molded product part solidifies is reduced, and the molding is performed. Insufficient molten metal due to solidification shrinkage during solidification of the product part is supplemented.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS. FIG. 1 shows a casting apparatus 1 for producing an inverted aluminum casting mold.
The casting apparatus 1 includes a casting frame 2 and a feeder lid 3 disposed on the casting frame 2.

The casting frame 2 is made of iron and forms a rectangular casting area. As shown in FIG. 3, a mold 4 made of ceramic (in this embodiment, porous mullite) is set in one half of the casting area.
At the center of the surface of the mold, a convex portion 4a that is higher than the periphery is formed. In addition, a board 5 formed in a flat shape with a refractory made of calcium silicate is set in the other half of the casting area.

On the other hand, as shown in FIG. 2, the feeder lid 3 has a first lid portion 6 made of a refractory and formed in a quadrangular prism shape.
And a second lid 7. On the side surfaces of the first and second lid portions 6, 7, through holes 6a, 7a are formed at four corners thereof so as to be orthogonal to the surfaces. The through holes 6a, 7
A connecting shaft 8 for connecting the first lid and the second lids 6 and 7 is inserted into a. Male screws 8 a are formed at both ends of the connecting shaft 8. Therefore, nuts 9 are provided at both ends of the connecting shaft 8 protruding from the side surfaces of the first and second lids 6 and 7.
The first lid 6 and the second lid 7
Are fixed with their side surfaces together. by this,
The feeder lid 3 is formed.

As shown in FIGS. 2 and 3, concave portions 10 each having a semicircular flat cross section are formed in the first and second lid portions 6 and 7 at the ends of the side surfaces facing each other. . The recess 10 includes a first recess 10a, a second recess 10b, and a third recess 10c. The inner diameter of the first recess 10a is larger than the inner diameter of the third recess 10c, and the inner diameter of the second recess 10b is continuously reduced from the inner diameter of the first recess 10a to the inner diameter of the third recess 10c. . When the side surfaces of the first lid part 6 and the second lid part 7 are combined to form the feeder lid 3, the recess 10 serves as a circular spout 11 as a circular spout as shown in FIG. 1. The upper part and the lower part of the feeder lid 3 are communicated.

After the feeder lid 3 is formed from the first lid 6 and the second lid 7, the feeder lid 3 is disposed on the casting frame 2. At this time, as shown in FIGS.
The feeder 11 communicates with a region in the casting frame 2 where the board 5 is set. Then, a first casting area 12 as a molded product part and a second casting area 13 as a non-molded product part are provided in a space surrounded by the bottom surface of the riser lid, the mold and the sintered material in the casting frame. And form. First casting area 12
Is an area surrounded by the mold 4 and the bottom surface of the feeder lid 3,
Cast aluminum reverse mold. Since the convex portion 4a is formed in the center of the mold 4, the first casting region 12 has a thin portion at the center and a thick portion around the center. The second casting area 13 is an area surrounded by the board 5 and the bottom of the feeder lid 3 and casts a non-product part. In addition, the feeder port 11 of the feeder lid 3 communicates with the second casting area 12.

Next, a method of casting an inverted aluminum casting mold using the casting apparatus 1 described above will be described. As shown in FIG. 4, molten aluminum as a molten metal is filled from the feeder 11 to all the casting regions 12 and 13, and furthermore, the feeder 1
Pour until 1 is full. Thereafter, the aluminum melted while being held in this state for a certain time is transferred to the first casting zone 1
Start to solidify from 2. This is because the first casting area 12 is
This is because the region is smaller than the casting region 13 due to the presence of the thin portion, and the molten aluminum in the feeder gate 11 is located on the second casting region 13 side. When the molten aluminum in the first casting region 12 solidifies, the temperature cooling gradient of the molten aluminum in the entire casting region is reduced by the presence of the molten metal in the second casting region 13 and the presence of the molten metal in the feed port 11. 1 casting area 12
Is only looser than if you were. That is, the molten aluminum gradually solidifies from the portion in contact with the casting frame 2. Therefore, the thin portion does not solidify last. Further, when the molten aluminum solidifies even when the temperature gradient becomes gentle, there is a portion where the molten metal becomes insufficient due to solidification shrinkage. In this part, the riser 11
The molten aluminum is replenished by the weight of the aluminum inside.

As described above, in the first casting region 12, the molten aluminum is gradually solidified, and the aluminum is solidified while replenishing the molten aluminum in a portion where the molten metal is insufficient. Therefore, burrows and dents due to the occurrence of shrinkage cavities do not occur in the aluminum casting reverse mold 14 cast in the first casting region 12.

After the aluminum in each of the casting regions 12 and 13 and the feeder opening 11 is completely solidified, the nut 9 fixing the first lid 6 and the second lid 7 constituting the feeder lid 3 is fixed. Is removed, and the first lid 6 and the second lid 7 are divided. Further, the aluminum obtained by removing the casting frame 2 is separated from the first casting area 12 and other parts. This makes the aluminum casting reversal mold 14
Can be obtained by itself. Here, the first lid part 6 and the second lid part 7 can be used again, and the cut-out portion of aluminum can be melted again and reused.

Next, the characteristic operation and effect of the above embodiment will be described below. (1) In the present embodiment, a first casting area 12 for casting a product part of an aluminum casting reverse mold and a second casting area 13 for casting a non-product part are provided in a casting frame 2. Thereby, the molten aluminum filled in the first and second casting regions 12 and 13 can have a gentle temperature cooling gradient during solidification. Therefore, since the molten aluminum is gradually solidified, burrows and dents generated in the thin portion of the aluminum casting reverse mold 14 cast in the first casting region 12 can be suppressed.

(2) In the present embodiment, a first casting area 12 for casting a product part of an aluminum casting reverse mold and a second casting area 13 for casting a non-product part are provided in the casting frame 2.
A feeder lid 3 provided with a feeder port 11 communicating with the second casting area 13 is disposed above the upper end of the feeder. As a result, the first and second
The molten aluminum filled in the casting regions 12 and 13 and the feed port 11 can moderate the temperature cooling gradient during solidification. Further, the aluminum in the first casting region 12 is melted by the weight of the aluminum in the feeder port 11 and supplied to the molten metal shortage generated when the aluminum in the first casting region 12 is solidified. Solidifies. Therefore, shrinkage cavities do not occur in the aluminum casting reversal mold 14 cast in the first casting region 12, and burrows and depressions can be suppressed.

(3) In the present embodiment, the feeder lid 3 is composed of the first lid part 6 and the second lid part 7, so that after the aluminum solidifies, the feeder lid 3 is broken. Solidified aluminum can be obtained without any problems. Therefore, the riser lid 3 can be reused.

The present invention can be embodied in another embodiment as follows. (1) In the above embodiment, the molten aluminum is fed to the feeder 11
Is poured until it becomes full, but it may be poured to any position as long as it is poured until the height of the casting frame 2 becomes higher. However, in order to supply the molten aluminum to the melt-deficient portion generated in the first casting area 12 by the own weight of the aluminum poured into the feeder port 11, the effect of eliminating the shrinkage cavities by increasing the full weight becomes larger when filled up. large.

(2) In the above embodiment, the mold 4 is made of ceramic, but is not limited to this, and may be made of, for example, sand or metal. (3) In the above embodiment, the board 5 is formed of a refractory made of calcium silicate, but the material of the refractory is not limited to this.

(4) In the above embodiment, the mold 4 has the projection 4a at the center thereof, but the surface shape of the mold 4 is not limited to this. (5) In the above embodiment, through holes 6a, 7a are formed in the first and second lid portions 6, 7, and the connecting shaft 8 having male threads 8a formed at both ends is inserted into the through holes 6a, 7a. Thus, the first and second lids 6 and 7 are fixed. Alternatively, the connecting shaft 8 may be fixed to one of the first and second lids 6 and 7, and only the other lid may be fixed by the nut 9.

(6) In the above embodiment, the feeder port 11 of the feeder lid 3 is circular, but the shape is not limited to this, and may be, for example, elliptical or square. (7) In the above embodiment, two through holes 6a, 7a are formed on the four corners of the first and second lids 6, 7, that is, two on each side, but one on each side. Is also good. In this case, a total of two connecting shafts are inserted into the through holes.

(8) In the above embodiment, molten aluminum was used as the molten metal, but the invention is not limited to this.
For example, nonferrous metals such as zinc and magnesium may be used. While the embodiments of the present invention have been described above, technical ideas other than the claims that can be grasped from the embodiments will be described below along with their effects.

(1) The casting method according to claim 2, wherein the feeder lid (3) comprises a first lid (6) and a second lid (7). Thereby, after the molten metal is solidified, a product is obtained without breaking the feeder lid 3. The feeder lid 3 is reused.

(2) The casting apparatus according to claim 4, wherein the feeder lid (3) comprises a first lid (6) and a second lid (6). Thereby, after the molten metal is solidified, a product is obtained without breaking the feeder lid 3. The feeder lid 3 is reused.

[0029]

As described above in detail, according to the present invention, it is possible to produce a molded article in which burrows and depressions caused by shrinkage cavities are suppressed.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a casting apparatus according to an embodiment.

FIG. 2 is a perspective view showing a feeder lid of the embodiment.

FIG. 3 is a sectional view taken along line AA.

FIG. 4 is a cross-sectional view when molten aluminum is poured into the casting apparatus of the present embodiment.

FIG. 5 is a sectional view of a conventional casting frame.

[Explanation of symbols]

Reference numeral 2 denotes a casting frame, 3 denotes a feeder lid, 11 denotes a feeder serving as a spout, 12 denotes a first casting area as a molded product part, and 13 denotes a second casting area as a non-formed product part.

Claims (4)

[Claims] 1. A molded product part (12) and a non-molded product part (13) are formed in a casting frame (2), and a molten metal is poured into the casting frame (2) to melt the molded product part (12). A casting method in which a temperature cooling gradient when solidifying is reduced. 2. A molded product part (12) and a non-molded product part (13) are formed in a casting frame (2), and a spout (11) is provided at an upper part of the casting frame (2). (1
A feeder lid (3) communicating with 3) is provided, and the molten metal is poured from the pouring port (11) of the feeder lid (3) to a height equal to or higher than the casting frame (2). ), The temperature cooling gradient when the molten metal is solidified is reduced, and the molded product part (1)
2) A casting method in which a shortage of molten metal due to solidification shrinkage during solidification is supplemented. 3. A casting apparatus in which a molded product part (12) and a non-molded product part (13) are formed in a casting frame (2). 4. A molded product part (12) and a non-molded product part (13) are formed in a casting frame (2), and a spout (11) is provided at the upper part of the casting frame (2). (1
A casting apparatus provided with a feeder lid (3) communicating with 3).