JPH05138324A - Casting method using inserting core and product thereof - Google Patents

Abstract

PURPOSE:To prevent the development of shrinkage cavity and the breakage of a core die by holding an inserting core with the core die having an inserting core holding part and a movable die and casting in the condition of holding the inserting core in a die cavity. CONSTITUTION:The inserting core 4 is fitted by inserting into the inserting core holding part 6a formed in the core die 5. At the position corresponding to the inserting core holding part 6a in the inserting core 4, core die fitting holes 7a are formed. By executing die clamping of a fixed die and a movable die and also core insertion of the core die 5, a movable die abutting projection 8 formed in the inserting core 4 is abutted on the movable die, and the inserting core 4 is held in the cavity. Molten alloy is filled up into the cavity from a sprue at high speed. By casting under this condition, cooling of the molten metal is improved and the generation of the shrinkage cavity is prevented. The length of projecting part, 55 of the core die 5 for forming a groove part in the thick part 2 of a casting product can be shortened at the irreducible minimum.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a casting method using a cast core and a product thereof, which can be suitably applied to, for example, the production of a die cast product having a thick portion that cannot be removed by cutting. And a product obtained by the method.

[0002]

2. Description of the Related Art Conventionally, in the production of a die cast product having a thick portion having a groove, for example, as shown in FIG. It has been performed to prevent the formation of shrinkage cavities by thinning the portion 20 and promoting cooling of the thick portion 20. And, in this method, the cast core was not used.

On the other hand, the applicant of the present application has proposed a casting method and a product thereof using a cast iron core (see JP-A-1-99766). In this method, when a core or a filling metal cannot be used to form a casting hole, a cast-in core made of the same material as the casting material is cast around, and after casting, the cast-in core is cut. This is a method of manufacturing a die-cast product having no porosity on the cut surface by removing and forming holes.

[0004]

However, if the groove portion 30 of the die cast product 10 is formed deeper than necessary,
In the above method of preventing sinkholes by thinning the thick portion 20 to accelerate the cooling of the thick portion 20, if the depth of the groove portion 30 is made larger than necessary, the die cast product 10 Since the length of the protrusion 40 of the groove 40 is relatively long, the hot water around the protrusion 40 is deteriorated and the groove 3
There is a problem that the tip portion of the protrusion 60 formed on the core die 50 for forming 0 is overheated to cause seizure, and the core die 50 is damaged when the core die 50 is pulled out. there were.

On the other hand, the method disclosed in Japanese Unexamined Patent Publication No. 1-99766 is a casting method for forming a hole in a die-cast product, and in this method, it is necessary to remove the cast-molding core by cutting. Therefore, it cannot be applied to, for example, the production of a die cast product having a thick portion that cannot be cut and removed, and has a drawback that it is not versatile.

The present invention has been made under such circumstances, and an object of the present invention is to reduce the depth of the groove portion of the thick portion even when casting a product having a thick portion having a protrusion. It is possible to minimize the required amount, it is possible to prevent the occurrence of shrinkage cavities, it is possible to prevent damage to the core die, and for example, for die-cast products having a thick portion that cannot be cut and removed. It is an object of the present invention to provide a versatile casting method that can be suitably applied to casting and a casting product obtained by suitably adopting this casting method.

[0007]

Means for Solving the Problems The structure of the present invention for attaining the above-mentioned object is to use a cast iron core for casting a die cast product having a thick portion provided with a projection using a cast iron core. In the casting method described above, a cast iron core made of the same material as the casting material is held by a cast iron core holding portion provided in the core die, and the mold is held by the core die and the movable die. Use of a cast core having a step of holding in a cavity and a step of filling a mold cavity with molten metal and taking out a cast product from the mold after solidification of the molten metal is completed. It is a casting method, which is a casting core made of the same material as the casting product, and is held in the mold cavity by being sandwiched between a core die having a casting core holding portion and a movable die. Specially made by casting And a cast product that, insert casting core holding portion abuts formed recess of the core die is the cast product having a through-hole formed by drilling.

[0008]

In the casting method using the cast-gurn core of the present invention, first, the cast-gurn core is set in the cast-gurn core holding portion formed in the core die, and the cast-gurn core is set in the core. Let the child die hold it. Next, the cast-molded core is sandwiched between the core die and the movable die. As a result, the cast iron core made of the same material as the cast product is held in the mold cavity. In this way, the molten metal is filled into the mold cavity in which the cast core is held, and after solidification is completed, the die-cast product is taken out from the mold cavity. In this casting method, since a cast core is used, even if the die-cast product has a thick portion with projections, the depth of the groove portion of the thick portion should be minimized to the required minimum. You can Therefore, the length of the protrusion can be minimized, and the hot water around the tip of the protrusion does not deteriorate. Further, the length of the protrusion of the core die for forming the groove in the thick portion may be the minimum required length, and the tip of the protrusion is not overheated to cause seizure. Therefore, when the core die is pulled out, the core die is not damaged. Moreover, the cast product obtained by this method does not require cutting and removal of the cast core, and this method can be suitably applied to, for example, the production of a die-cast product having a thick portion that cannot be cut and removed. ..

[0009]

Embodiments of the present invention will now be described in detail with reference to the drawings. In this embodiment, as shown in FIGS. 1 and 2, a die cast product 3 having a thick portion 2 having a protrusion 1 is manufactured. Prior to casting, casting material (eg JI
The cast core 4 is cast using the same material as the S standard die casting alloy ADC10).

The cast-gurnette core 4 is fitted into and mounted on the cast-gurgling core holding portions 6a, 6b, 6c formed on the core die 5. Specifically, the cast core holder 6
a, 6b and 6c are formed on the core die 5 in a projecting shape, and the cast iron core 4 is preliminarily provided at a position corresponding to each of these cast iron core holding portions 6a, 6b and 6c. Die mounting holes 7a, 7b, 7c are formed.
That is, insert the cast iron core holding portions 6a, 6b, 6c formed in the core die 5 into these core die mounting holes 7a, 7b, 7c formed in the cast core 4. Then, the cast core 4 is mounted on the core die 5. In addition, it is desirable that the number of the cast iron core holding portions formed on the core die 5 is plural, and in this embodiment, three points 6a, 6b and 6c are formed as described above. Further, the number of core die attachment holes formed in the cast metal core 4 is the same as the number of the cast metal core holding portions.

Next, a fixed die and a movable die, both of which are not shown (in this embodiment, the movable die is provided on the front side in the direction perpendicular to the paper surface of FIG. Is provided), and the core is inserted into the core die 5 to obtain the state shown in FIG. In this way, the fixed die and the movable die are clamped, and the core die 5
When the inner core is inserted, the movable die contact projection 8 formed in the cast-molded core 4 in a protruding shape abuts on the movable die,
As a result, the cast iron core 4 is held in the cavity.

Then, from a sprue (not shown), for example, JIS
The molten metal of the alloy ADC10 for standard die casting is filled into the cavity at high speed. The casting conditions at this time are usually appropriately determined within the following range.

That is, the mold temperature is about 200 to 250 ° C, and the hot water temperature is about 650 to 700 ° C. The casting pressure (gauge pressure) is 500 to 1000 kg / cm.
^The casting speed (gate speed) is about ² to 40 m /
It is about a second.

In the casting performed under such conditions, the use of the cast-molded core 4 accelerates the cooling of the molten metal and prevents the formation of shrinkage cavities. Further, the core die 5 to be used is provided with the protrusion 55 for forming the groove portion of the thick portion 2 of the die cast product 3. In this method, the cast core 4 is used. By doing so, the cooling of the molten metal is promoted, so that the length of the protrusion 55 can be minimized. Therefore, seizure of the tip of the protrusion 55 is prevented, and damage to the core die 5 is prevented.

After the molten metal has been filled into the cavity at a high speed as described above, a fixed die and a movable die are opened after the molten metal is solidified, and the core die 5 is removed. Then, the desired die-cast product 3 is taken out.

Die-cast product 3 manufactured in this way
As shown in FIG. 1, is a thick portion 2 having a plurality of protrusions 1.
The thick portion 2 may not be cut and removed.

Further, the core die mounting holes 7a, 7b, 7c included in the die cast product 4 included in the die cast core 4 are provided.
All or a part of the recesses 9a, 9b and 9c corresponding to may be further perforated to form a through hole.
This perforation can be easily performed by using a drill, for example.

[0018]

EFFECTS OF THE INVENTION According to the present invention, because of the above-mentioned constitution, it is possible to prevent the occurrence of shrinkage cavities even when casting a product having a thick portion provided with a projection, and to perform core die It is possible to prevent the damage of the casting, and it is also suitable for casting die-cast products having a thick portion that cannot be removed by cutting. It is possible to provide a cast product obtained by the adoption.

[Brief description of drawings]

FIG. 1 is a side view showing an example of a cast product of the present invention.

FIG. 2 is a sectional view taken along the line AA of FIG.

FIG. 3 is an explanatory cross-sectional view showing the relationship between a conventional cast product and a core die.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Protrusion 2 ... Thick part 3 ... Die cast product 4 ... Casting core 5 ... Core die 6a, 6b, 6c ... Casting core holding part 9a, 9b, 9c ... Recessed part

Claims (3)

[Claims] 1. In a casting method using a cast-in-gured core, a die-cast product having a thick portion having a projection is cast using the cast-in-gured core, and a cast-in-mold core made of the same material as the casting material is used. A step of holding the casting die core holding portion provided in the core die and holding it in the mold cavity by sandwiching it between the core die and the movable die; and filling the mold cavity with molten metal. And a step of taking out a cast product from a mold after solidification of the molten metal is completed, a casting method using a cast-in-mold core. 2. A state in which a cast core made of the same material as the cast product is held in a mold cavity by being sandwiched between a core die having a cast core holding portion and a movable die. A cast product characterized by being cast. 3. The cast product according to claim 2, further comprising a through hole formed by boring a concave portion formed in contact with a cast core holding portion of the core die.