JP2005205412A - Core and die - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem that gas generated by teeming intrudes into the molten metal to cause a defective casting when a casting is cast using a die set with a non-gas permeable core molded using nitrate and/or nitrite. <P>SOLUTION: Regarding the non-gas permeable core molded using nitrate and/or nitrite, a plurality of linear projection parts or grooves capable of dividing vent passages allowing the inside of a cavity 2 in a die 1 to communicate with the open air in a space with the faces of cavities 3 are provided at the contact positions with the faces of the cavities 3 for a core print set. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to improvements in non-breathable cores and molds made using nitrate and / or nitrite.

In recent years, castings have been performed using a mold in which a non-breathable core formed using nitrate and / or nitrite is set.

However, since the above-described core and mold have no air permeability, the pressure of the gas generated by pouring has partially pushed the molten metal to cause gas defects such as dents in the casting.
Special table 2003-503210 gazette

  The problem to be solved is that the pressure of the gas generated by pouring melts when casting a casting using a mold set with a non-breathable core made of nitrate and / or nitrite. This is a point in which the metal is partially pushed to cause a gas defect such as a dent in the casting.

  The core of the present invention is a non-breathable core formed by using nitrate and / or nitrite, and a vent path that communicates the inside of the mold cavity with the outside air is provided as a cavity for setting the core baseboard in the mold. A plurality of linear protrusions or grooves that can be defined by a surface are provided at a position of contact with the cavity surface for setting the core baseboard.

In the present invention, the nitrate includes strontium nitrate, potassium nitrate, sodium nitrate and the like.
In the present invention, nitrites include potassium nitrite and sodium nitrite.
In the present invention, the height of the protrusion or the depth of the groove is preferably 1.0 to 0.1 mm, and if it exceeds 1.0 mm, the inside of the air passage formed by the core and the mold The molten metal enters into the cast iron, causing burrs and the like in the casting.
Furthermore, the nitrate and / or nitrite can be reliably used as a core material by containing strontium nitrate as a main component.

The present invention relates to a non-breathable core formed using nitrate and / or nitrite,
A linear protrusion or groove capable of defining a vent path communicating with the inside of the mold cavity and the outside air with the core baseboard set cavity surface in the mold, and the core baseboard set cavity surface Since the gas generated by pouring is discharged to the outside through the air passage that communicates the inside of the cavity and the outside air, gas defects such as dents are generated in the casting due to the gas pressure. Excellent practical effects such as being able to be prevented are exhibited.

  Hereinafter, the best mode for casting a casting by applying the present invention will be described in detail with reference to the drawings. On the mating surfaces of the mold pieces 1 of the vertically split mold, there are the product cavity 2, the core baseboard setting cavity 3 for setting the core baseboard, the core baseboard setting cavity 3 and the outside air. A communicating cavity 4 and a gate cavity 5 communicated with each other. And the core 7 provided with the base board 6 at the front-end | tip in the said product cavity 2 and the said core base board set cavity 3 in the one metal mold piece 1 among the said two metal mold pieces 1.1. Is inserted and set in the cavity 3 for setting the core skirting board.

By inserting the skirting board 6 into the core skirting board setting cavity 3, an air passage that communicates the inside of the mold cavity with the outside air is formed. The core 7 is manufactured by heating and melting a salt obtained by adding 10 parts of potassium nitrate to 100 parts of strontium nitrate, and then pouring it into a mold. Thus, a plurality of grooves 8 having a depth of 0.3 mm are formed.

As described above, a molten aluminum alloy is formed in a cavity formed by combining two mold pieces 1 and 1 of the mold piece 1 with the core 7 set and the mold piece 1 without the core 7 set. Is injected into the gate cavity 5, and the gas generated by the injection of the molten aluminum alloy is discharged to the outside through the grooves 8 and 8 of the skirting board 6 of the core 7 and the ventilation cavity 4. After the molten aluminum alloy thus injected is hardened, the aluminum alloy with a built-in core 7 is taken out from the two mold pieces 1, 1, and the core alloy with a built-in core is immersed in warm water to remove the core. As a result of elution and removal, an aluminum alloy casting having about 2% of defects could be obtained.

In order to verify the effect of the present invention, a core without a groove in the baseboard was formed using the salt described above, and then an aluminum alloy casting was cast using the core in the same manner as described above. Gas defects such as dents due to gas pressure were observed throughout the casting.

In the above-described embodiment, the air passage that communicates the inside of the mold cavity with the outside air is formed by the groove 8 of the baseboard 6 and the mold. However, the present invention is not limited to this, as shown in FIG. In addition, a plurality of protrusions 9 extending in the longitudinal direction of the skirting board 6 are provided on the outer surface of the skirting board 6 or, as shown in FIG. 4, on the surface of the cavity 3 for setting the core skirting board in the mold in the longitudinal direction. Of course, even if a plurality of extending grooves 10 are provided or a plurality of protrusions 11 are provided on the surface of the core baseboard setting cavity 3 in the mold as shown in FIG. .

It is a front view of the mating surface of the metal mold | die piece concerning the metal mold | die and core for implementing this invention. It is an AA arrow line view in FIG. It is 2nd Example which concerns on FIG. It is 2nd Example which concerns on FIG. It is 3rd Example which concerns on FIG.

Explanation of symbols

1 Mold piece

3 Cavity for core core baseboard set

6 Baseboard

7 core

8; 10 groove

9; 11 Projection

Claims (5)

In a non-breathable core molded with nitrate and / or nitrite,
A linear protrusion or groove capable of defining a vent path communicating with the inside of the mold cavity and the outside air with the core baseboard set cavity surface in the mold, and the core baseboard set cavity surface A core provided with a plurality of contact positions.  The core according to claim 1, wherein the height of the protrusion or the depth of the groove is 1.0 to 0.1 mm. The core according to claim 1 or 2, wherein the nitrate and / or nitrite contains strontium nitrate as a main component. In a mold for casting a casting by setting a non-breathable core formed using nitrate and / or nitrite,
A linear protrusion or groove that can define an air passage that communicates the inside of the mold cavity with the outside air with the core baseboard for core baseboard setting for setting the core baseboard A mold having a plurality of cavities. The mold according to claim 3, wherein the height of the protrusion or the depth of the groove is 1.0 to 0.1 mm.