JPH06210440A - Casting method and casting mold - Google Patents

Abstract

(57) [Summary] [Purpose] To prevent the occurrence of cracks at the position farthest from the molten metal supply port. [Structure] A space portion 18 is arranged so as to face a product edge forming portion at a position farthest from the molten metal supply port 12, and the space portion 18 is communicated with a cavity 10 through a weir hole 20. The melt supply port 12 is connected to the left end of the cavity 10 via the main runner 14 and the weir 16 and to the space 18 via the sub runner 22.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a casting method and a casting mold.

[0002]

2. Description of the Related Art When molding a component having a desired shape by casting, it is necessary for the molten metal to uniformly spread over the entire region of the component molding cavity in a short time. For example, if a molten metal supply port is provided near one end of the cavity and the molten metal is supplied only from that molten metal supply port, the molten metal will spread to the vicinity of that one end in a short time. It takes a considerable amount of time for the molten metal to reach the other end at the farthest position. Therefore, when the molten metal reaches the other end, the temperature of the molten metal is also lowered, so that the molten metal solidifies quickly, and the tissue near the other end tends to become a chilled structure. Chilled tissue is fragile,
Cracks are likely to occur in the molded parts. In casting, in order to avoid the formation of the chilled structure, as described above, the most important issue is to uniformly supply the molten metal to the entire region of the cavity within a short time.

As a method for solving this problem, there is a casting method described in Japanese Patent Laid-Open No. 3-151138. In this casting method, a plurality of molds are arranged symmetrically in the vertical direction, and a molten metal supply port is provided from the center position. A branch passage is formed from this molten metal supply port to the center of each mold, and the molten metal is supplied from the center of the cavity for molding a cast component. In this way, by casting from the center of the cast part,
The hardness can be averaged and the accuracy can be improved.

[0004]

However, even if the molten metal is supplied from the center of the cast part, it takes the longest time for the molten metal to reach the end of the cast part. Therefore, it takes time for the molten metal to reach the end, and when the molten metal reaches the end, the molten metal temperature decreases,
The molten metal solidifies faster by that amount, which causes a chilled structure. In particular, when the end of the cast part has a shape larger than that of the center and has a shape protruding outward, it is even more necessary for the molten metal to circulate at this end. Since it takes time, a chilled structure is likely to occur at this end.

Further, in the casting method described in the above publication, the molten metal is supplied to each mold from the molten metal supply port through the branch passage, so that the molten metal is molded into parts as compared with the case where the molten metal is directly supplied to the mold. It takes a long time to fill the inside of the cavity. The present invention has been made in view of the above problems, and a casting method and a casting mold capable of uniformly supplying molten metal to a portion where cracks are likely to occur in a short time and preventing the occurrence of a chilled structure. The purpose is to provide.

[0006]

To achieve this object, in the casting method according to the present invention, the molten metal is supplied to the product section through a runner connected to the product section, and the runner and the product section are connected. The molten metal is supplied to the product part through a space part connected to the product end part farthest from the connection part.

Further, the casting mold according to the present invention is provided at a position farthest from the main runner for guiding the molten metal supplied from the molten metal supply port to the product part and the connecting part between the main runner and the product part. A space portion that is arranged to face a certain product edge forming portion and communicates with the product edge forming portion, and a sub runner that communicates the space portion and the molten metal supply port. In a preferred embodiment, the space portion is formed so as to project outward from the product edge forming portion.

As will be seen from the examples described later, the casting mold according to the present invention is particularly useful when the shape of a part at the position farthest from the molten metal supply port is the largest shape of the part.

[0009]

1 and 2 show one embodiment of a casting mold according to the present invention. A cavity 10 having the same outer shape as the desired shape of the part is formed inside the mold (for the sake of clarity, only the cavity 10 is shown, and the mold around it is not shown).

A molten metal supply port 12 extending in the direction perpendicular to the drawing is formed in the mold. A main runway 14 extends from the molten metal supply port 12, and a cavity 10 is provided via a weir port 16.
Is connected to the left end part of. As is apparent from FIG. 1, the part cast by the cavity 10 has a shape in which the right end portion is larger than the left end portion. Normally, since the molten metal is supplied to the cavity 10 only through the main runway 14, the molten metal reaches the right end portion at the latest. Therefore, the right end portion is the portion where the chilled structure is most likely to occur, and therefore cracks are likely to occur (the portion shaded in FIGS. 1 and 2). Further, in the present embodiment, the part cast by the cavity 10 projects most outwardly at this right end portion, and is the portion most likely to be impacted by falling during the production process or contact with other hard substances. It has become.

A space 18 is formed adjacent to the right end portion of the cavity 10. The space 18 is shown in FIG.
As shown in FIG.
Cavity 10 that easily cracks through 0
It communicates with the right end part of the. Further, the space portion 18 is formed so as to protrude outwardly from the outer periphery of the right side portion of the cavity 10. That is, as shown in FIG. 1, the space 18 projects a length T outward from the outer periphery of the cavity 10.

The space 18 is connected to the molten metal supply port 12 via a sub runner 22. The molten metal supplied from the molten metal supply port 12 passes through the main runway 14, enters the inside of the cavity 10 from the left end of the cavity 10 through the weir port 16, and passes through the sub runway 22 and the space 18 and The cavity 10 is entered from the right end of the cavity 10 through the weir 20. Therefore, the molten metal in a high temperature state can be supplied to the right end of the cavity 10 where cracks are likely to occur, and the occurrence of cracks at the right end can be effectively prevented.

Although the embodiments described above relate to casting molds, this embodiment also corresponds to an embodiment of the casting method according to the present invention. That is, in the casting method according to the present invention, the sub runner 22 and the space portion 18 are provided at the right end of the cavity 10 at the farthest position from the weir 16 that connects the main runner 14 and the cavity 10. Since the method includes the step of supplying the molten metal, the present method can also supply the molten metal in a high temperature state to a portion where cracks are likely to occur, and can effectively prevent the occurrence of cracks.

[0014]

EFFECT OF THE INVENTION In the casting mold according to the present invention, in the conventional method, the molten metal is supplied first to the portion where the molten metal reaches the latest, so that the formation of a chilled structure in that portion and the occurrence of cracks are prevented. You can do it. In particular, as shown in the embodiment, when the part farthest from the molten metal supply port is the largest in the part and further has a shape that projects greatly outward, only one molten metal supply port is provided. If this is not the case, the molten metal will reach this portion and the time for the molten metal to fill this portion will be extremely delayed, which will promote the generation of a chilled structure in this portion. The casting mold according to the present invention is extremely effective in such a case.

In addition, by providing a space facing the end of the product and supplying the melt to this space, the melt supplied to the end of the product can be kept warm and chilled at the end of the product. It is also possible to suppress the generation of tissue. Further, since the space portion in the main casting mold is formed so as to project outward from the cavity, when the cast-molded part is taken out of the mold, the space portion is in a state of protruding to the outermost side. For this reason, even if the cast part is impacted by falling or contact with another hard substance during the movement to another process, the space part first absorbs the impact to some extent. It is possible to prevent damage to some extent.

Also in the casting method according to the present invention, in the conventional method, the molten metal is supplied first to the portion where the molten metal reaches the latest, so that the formation of the chilled structure in that portion and the occurrence of cracks are effectively prevented. can do.

[Brief description of drawings]

FIG. 1 is a plan view of a casting mold according to the present invention.

FIG. 2 is a side view seen from the right in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Cavity 12 Molten metal supply port 14 Main runway 16 Weir 18 Space part 20 Weir 22 Sub runner

Claims (3)

[Claims] 1. The molten metal is supplied to the product section through a runner connected to the product section, and the molten metal is passed through a space section connected to a product end farthest from the connection section between the runner and the product section. Casting method to supply the product to the product department. 2. A main runner that guides the molten metal supplied from the molten metal supply port to the product part, and a product edge forming part that is farthest from the connection part between the main runner and the product part. And a sub-runner that connects the space portion and the molten metal supply port to each other. 3. The casting mold according to claim 2, wherein the space portion projects outward from the product edge forming portion.