JPH0576644U - Sprue structure of casting mold - Google Patents

Abstract

(57) [Summary] [Purpose] To prevent melting damage when pouring molten metal. [Constitution] The sprue 10 connected to the runner portion is formed in an inverted conical shape, and the runner communication portion 1 is formed from the lower opening 12 of the sprue 10.
The part up to 3 is made smooth so as to minimize melting loss that occurs when pouring molten metal.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a sprue structure in a casting mold in which melting loss during pouring of molten metal is prevented as much as possible and the flow of molten metal is made smooth.

[0002]

[Prior Art]

 Gravity casting using a die is generally used to cast products with relatively complex shapes such as camshafts. In this gravity casting, a sprue for receiving the molten metal is usually provided in the upper part of the die, and the molten metal is introduced into the cavity inside the die through the sprue.

Here, FIG. 3 shows a sprue part of a mold generally used in the past, and this sprue a has a bowl shape so that a large amount of molten metal can be surely received at the time of pouring. Therefore, the one having a large internal volume is used.

However, in such a sprue structure, the portion from the lower end opening of the sprue a to the runner portion c has a large curvature and is sharply narrowed. However, there is a problem in that the bent portion b is melted by the heat of the molten metal reaching a temperature of about 1400 ° C., and sometimes the melted portion is cracked and the gate a is damaged.

[0005]

[Problems to be solved by the device]

 The present invention has been made in view of such problems, and an object thereof is to provide an improved sprue structure capable of smoothing the flow of the molten metal while preventing the melting loss and the like generated at the time of pouring the molten metal as much as possible. To provide.

[0006]

[Means for Solving the Problems]

 That is, in the present invention, as a sprue structure for achieving the above object, by forming a sprue connected to the runner part in an inverted conical shape and smoothly forming a flow path from the lower opening of the sprue to the runner part The flow pressure of the molten metal at the time of pouring is reduced as much as possible to minimize the melting loss in this part and to make the molten metal flow to the runner part smooth.

[0007]

【Example】

 Therefore, the embodiment illustrated below will be described. FIG. 1 schematically shows the sprue structure according to the present invention divided into two parts, and FIG. 2 shows the whole of a mold having this structure.

A sprue 10 which will be described later is provided on the upper part of the die 1, and a horizontal runner portion 5 extending further laterally is connected to a spout bottom 4 of a vertical runner portion 3 communicating with the sprue 10. Product-shaped cavities 6 are formed here, and the molten metal injected from the sprue 10 is configured to be filled in the respective cavities 6 inside the mold through the runners 3 and 5. .

As shown in FIG. 1, the above-mentioned sprue 10 in the mold 1 is provided with a molten metal reservoir 11 for receiving molten metal and a cylindrical communication portion 12 extending from the molten metal reservoir 11 to the runner portion 3. Therefore, the basin 11 is formed in an inverted conical shape so that the diameter r of the lower opening 13 is smaller than the diameter R of the upper end opening 14.

The inner peripheral surface 15 of the basin 11 is inclined substantially linearly toward the communicating portion 12, and the opening angle α at which the extension lines intersect is set in the range of 30 to 90 °. . Therefore, the portion connecting the lower opening 13 of the sprue 10 to the communication portion 12 is configured so that the hot water flows smoothly by forming a small ar.

If the opening angle α is smaller than 30 °, the internal volume of the basin 11 becomes too small, and if the opening angle α is larger than 90 °, the lower opening 13 leads to the communicating portion 12. The curvature of the portion becomes large, and the pressure of the hot water hitting the communication portion 12 becomes large.

[0012]

[Effect of the device]

 As described above, according to the present invention, the portion of the sprue that is connected to the runner portion is formed into an inverted conical shape so that the flow path is gently formed. It is possible to minimize the melting loss and reduce the internal volume of the molten metal reservoir to reduce the required amount of molten metal as much as possible.

[Brief description of drawings]

FIG. 1 is a perspective view showing a sprue structure according to the present invention in a divided manner.

FIG. 2 is a view showing the whole of a mold having this sprue structure.

FIG. 3 is a view showing a conventional sprue structure.

[Explanation of symbols]

 10 Yukou 11 Hot water reservoir 12 Communication part 13 Lower opening

Claims (1)

[Scope of utility model registration request] 1. A sprue structure for a casting mold, wherein a sprue connected to a runner portion is formed in an inverted conical shape, and a flow path from a lower opening of the sprue to the runner portion is formed smoothly.