JPH03155446A - Method for cooling die for casting - Google Patents

Abstract

PURPOSE:To cool only locally heated position in a die in a short time by directly bringing the locally heated position in the die into contact with coolant charged in a vessel after releasing a casting product from the die and cooling. CONSTITUTION:By opening the die 2, the casting product is released from the die 2. After that, the locally heated position (pin part) 21 in the die 2 is directly brought into contact with the coolant (facing material) 8 charged in the vessel 7 and cooled. Then, the vessel 7 is descended and the die 2 is set to restart casting. To upper part of the vessel 7, a covering member 9 with a hole 91 bored corresponding to the pin part 21 is fitted. At the time of descending the vessel 7, by bringing the circumferential edge of the hole 91 in the covering member 9 into contact with the bolt pin 21, the facing material 8 is wiped off. By this method, the casting product can be uniformly solidified.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for cooling a casting mold, and particularly to a cooling method for cooling locally heated parts of a mold.

[Conventional technology]

Generally, in the case of low-pressure casting, for example, as shown in FIG.
Inside, a stalk 5 and a runner mold 6 installed below the lower mold 3
The molten metal is poured through the molten metal as shown by the arrow.

In this case, the regions indicated by symbols A, B, and C in FIG. 4 are locally heated because the molten metal collides with them during pouring. In addition, in order to form bolt insertion holes etc. of cast products,
The pin portion 21 formed on the upper mold 2 also has a large heat receiving area and a small volume, so that it is heated more locally than other parts.

Therefore, if casting is restarted as it is, the cast product will suffer from solidification failure, and shrinkage cavities will occur in the cast product, resulting in a defective product.

Therefore, in order to eliminate such defective casting products,
Methods are being considered to cool locally heated parts of the mold.

In this cooling method, a cooling passage is bored inside the mold itself, and a refrigerant is flowed through the cooling passage to cool the mold. However, with this method, the cooling effect extends to the entire mold, making it impossible to sufficiently cool local heated areas.
Since the mold itself is cooled from inside, it is not possible to directly cool the surface of the locally heated area, resulting in indirect cooling.
Cooling time was significantly increased. Furthermore, the long and narrow protrusions of the pins and the like, which tend to become locally heated parts, make it virtually impossible to form cooling passages therein.

Therefore, Japanese Unexamined Patent Publication No. 168267/1983 (Japanese Patent Application No. 934/1982) has been proposed as a method for quickly cooling a mold regardless of the shape of the mold.

In this method, a mold is cooled by injecting a refrigerant through a nozzle or the like. This allows the mold to be directly cooled by the refrigerant.

[Problem to be solved by the invention]

However, although this type of cooling method can shorten the cooling time for cooling the mold, the refrigerant may be injected to areas other than the locally heated areas that are being cooled, or the injected refrigerant may flow out. Parts that do not require cooling are cooled, and as a result, the cast product does not solidify uniformly during casting.
Shrinkage cavities occur and the cast product becomes defective.

Therefore, an object of the present invention is to quickly and sufficiently cool only the necessary parts of the mold.

[Means to solve the problem]

Therefore, in this invention, after the mold is opened and the cast product is released from the mold, the locally heated parts of the mold are brought into direct contact with a refrigerant placed in a container to be cooled. It is something.

[Effect]

According to the above method, only the locally heated parts of the mold can be cooled by direct contact with the refrigerant in the container, so the cast product solidifies uniformly during casting, so no defects will occur in the cast product. .

〔Example〕

Hereinafter, the present invention will be described in detail based on the accompanying drawings.

1 and 4 show an embodiment of the present invention, and FIG. 1 is an enlarged view of part A in FIG. 4 showing a mold cooling method;
FIG. 4 is a sectional view of a typical mold for low-pressure casting.

As shown in FIG. 4, the low pressure casting device has an upper die 2
A cavity 4 is formed in a mold 1 consisting of a lower mold 3 and a lower mold 3, and a runner mold 6 and a stalk 5 are disposed below the lower mold 3.

In such a low-pressure casting apparatus, during casting, the upper mold 2
Molten metal is poured into the cavity 4 formed by the lower mold 3 and the lower mold 3 via the stalk 5 and the runner mold 6 as shown by the arrow. After solidification of the molten metal is completed, the upper mold 2 is released from the lower mold 3 by a lifting means (not shown) and the cast product is taken out. Thereafter, the upper mold 2 is set in the lower mold 3 again and casting is restarted.

This is a casting method in which cast products are continuously manufactured by repeating such steps, and the upper mold 2 is separated from the lower mold 3.
After the solidified casting is removed, a step is added to cool down the locally heated parts of the mold.

Specifically, in the case of part A in FIG. 4, as shown in FIG. 1, a container 7 containing mold coating agent 8 as a refrigerant is raised by a lifting means (not shown), and the mold is locally coated. The pin part 21 serving as a heated part is immersed in the mold coating material 8 in the container 7 and brought into direct contact with the mold coating material 8, so that the heat of the pin part 21 is absorbed by the mold coating material 8. Thereafter, the container 7 is lowered, the upper mold 2 is set on the lower mold 3, and casting is restarted.

In addition, a hole 91 corresponding to the pin portion 21 is provided at the top of the container 7.
A lid member 9 having a hole therein is attached, and when the container 7 is lowered, the periphery of the hole 91 of the lid member 9 comes into contact with the bolt pin 21 and wipes off the coating material 8. Note that this lid member 9 is made of a material having elasticity, heat resistance, and water absorption properties, such as Kao Wool (trade name).

When the pin part 21 of the upper mold 2 is locally heated by the method described above, the pin part 21 can be directly cooled by the coating material 8 placed in the container 8, so that only the necessary parts are heated. , can be sufficiently cooled in a short time. Also,
As a result, when the casting is restarted, the molten metal solidifies uniformly, so that no shrinkage cavities or the like occur in the cast product.

Furthermore, when the container 7 is lowered after the pin portion 21 has been cooled by the coating agent 8, the lid member 9 attached to the container 7
The mold coating agent 8 adhering to the pin portion 21 can be wiped off, and this wiping can prevent the mold coating agent 8 from dripping.

Furthermore, since the mold coating agent 8 is placed in the container 7, the capacity of the mold coating agent 8 as a refrigerant can be increased, and the cooling capacity can be greatly improved.
The pin portion 21 can be sufficiently cooled in a shorter time.

Furthermore, the mold coating agent 8 is originally applied to improve the runnability and mold releasability, but the mold coating agent 8 is applied to areas of the mold 1 where there is a large temperature difference, that is, the pin area, which is a locally heated area. However, in this example, since the coating agent 8 was used as the refrigerant, the coating agent 8 can be applied at the same time as the pin portion 21 is cooled, so it is necessary to apply the coating agent again. There is less need for coating, and the process and man-hours can be shortened, and the original function of the mold coating agent 8 can be maintained. In addition, the coating can be corrected by applying only the parts where the coating agent 8 has peeled off, so the surface of the coating agent 8 can always be made uniform with no irregularities, improving the quality of the surface of the cast product. can do.

FIG. 2 is an enlarged view of section B in FIG. 4 showing a second embodiment of the present invention.

In this embodiment, the same reference numerals as in FIG. 1 are used for the parts corresponding to those in FIG. 1, and detailed explanation thereof will be omitted.

In the second embodiment shown in FIG. 2, the side surface 22 of the upper mold 2, which is a locally heated region, is cooled by raising the container 10 and bringing it into direct contact with the mold coating agent 11 inside the container 10. This is how it was done. Further, in the case of this embodiment, the mold coating agent 11 in the container 10 is forcibly circulated as shown by the arrow by the pump 12 to improve the cooling capacity.

Furthermore, the space between the upper end of the container 10 and the upper mold 2 is sealed by a lid member 13 attached to the container 10. Note that this lid member 13 is made of Kao Wool (trade name) as in the first embodiment.

FIG. 3 is an enlarged view of section C in FIG. 4 showing a third embodiment of the present invention.

In this embodiment, the same reference numerals as in FIG. 1 are used for the parts corresponding to those in FIG. 1, and detailed explanation thereof will be omitted.

In the third embodiment shown in FIG. 3, the container 14 is pressure-bonded to the side surface 23 of the upper mold 2 through the lid member 15, and the mold coating agent 16 inside the container 14 is covered with the lid. Member 15
The mold coating agent 16 is brought into contact with the side surface portion 23 and cooled.

Note that this lid member 15 is made of Kao Wool (trade name) as in the first embodiment.

In addition, in the above embodiment, the case where the pin part, the top surface part, and the side part of the mold were cooled was explained as an example, but the invention is not limited to this, and regardless of the shape of the mold, any・It can also be used to cool parts of the body.

Furthermore, although the explanation has been given using low-pressure casting as an example, the present invention is not limited to this, and any casting method may be used.

Further, although an example has been described in which a coating agent is used as the refrigerant, the present invention is not limited to this, and any refrigerant may be used.

〔Effect of the invention〕

As mentioned above, this invention brings the locally heated parts of the mold into direct contact with the refrigerant contained in the container.
Only the locally heated parts of the mold can be sufficiently cooled in a short time.

[Brief explanation of the drawing]

1 is an enlarged view of part A in FIG. 4 showing one embodiment of the present invention, FIGS. 2 and 3 are enlarged parts B and C of FIG. 4 showing another embodiment, and FIG. is a cross-sectional view of a mold in general low-pressure casting. １−−１−・−・・Mold 7−−−−・−・Container 8・−・・−・Mold coating agent (refrigerant)

Claims (1)

[Claims] After the mold is opened and the cast product is released from the mold, the locally heated parts of the mold are brought into direct contact with a refrigerant placed in a container to be cooled. Cooling method for casting molds.