JPH0687064A - Casting method using specific core - Google Patents

Abstract

PURPOSE:To provide a casting method using a special core, in which a cast product having wide range of the shapes can efficiently be formed without restricting the shape, by using the special core other than sand core conventially used as the core. CONSTITUTION:After forming a sheet metal core 1, the sheet metal core 1 is arranged between an upper die 2 and a lower die 3 to form a molding die 4 and successively, molten metal such as molten aluminum is poured into a cavity part formed in the molding die 4 according to the shape of the cast product. Successively, after molding the cast product 6 having the shape corresponding to the shape in the cavity part, the cast product 6 is taken out from the molding die 4, and in the state that the sheet metal core 1 is made as a part of the cast product 6 without taking out the core 1, and the unnecessary part such as burrs of this cast product 6 is removed to obtain an objective completed product. Since the molding die is formed by using the metal core, and the cast product is cast by using the molding die the improvement of the productivity and the enlargement of the application range is enabled, and the quality of the cast product can be improve and also, the cost of the cast product can greatly be reduced.

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 special core, and in particular, a casting method using a special core without using a sand core which has been conventionally generally used as a core. The present invention relates to a casting method using a special core that can be efficiently formed without being restricted by the shape even if it has a complicated shape such as a hollow shape or an undercut shape by obtaining a cast product.

[0002]

2. Description of the Related Art In casting adopted as a part of machining, a non-disintegrating core or a disintegrating core is used for casting to form a hollow portion or an undercut portion. I was getting.

By the way, as the former (non-disintegrating core), there is a metal core, but the conventional metal core is considered as a separate body from the cast product after casting, and is extracted from the cast product after casting. Since it was necessary, it could not be used except for those that could be directly punched or deformed, and the range of use was limited to those with a specific shape.

As the latter (disintegrating core), a sand core is generally used, but it is difficult to mold and
Not only is it easy to disintegrate and is difficult to handle, but it is also difficult to meet the conflicting conditions of pressure resistance during casting and disintegration after casting.

Therefore, in recent years, it has been proposed to obtain a cast product by casting using a core having a special coating on the surface of the sand core, but there are the following problems.
I couldn't solve the problem. (1) The coating is difficult because it is difficult to form not only one layer but also a plurality of layers. Therefore, not only the coating is time-consuming and labor-intensive, but also time and cost are required. It is difficult to achieve the initial purpose. (2) Since it is difficult to completely remove the binder which is a component of the coating layer and the sand core after casting, it is necessary to perform a sand baking treatment for removing the coating layer and the binder. It is time-consuming and costly. (3) Since the sand core is difficult to mold, it requires not only equipment and man-hours, but also the molded sand core is fragile and difficult to handle, and it requires man-hours and yield is poor.
It takes time and money. (4) Since the sand core requires pressure adjustment to prevent collapse during casting, and complete collapse after casting is difficult, a heat treatment step, sand drop step, and sand drop inspection are required. It requires man-hours and is time-consuming and costly. (5) It is easy to generate defective products such as a molten metal being inserted between sand particles of a core during casting, and a component of the sand core penetrating into a cast product to cause a cavity in the cast product, Casting yield is poor and productivity is poor. (6) It is difficult to completely remove the core sand after casting, and it adheres to the cast product, causing problems such as wear and damage of the product. (7) Since the casting of complicated shapes and large castings are difficult or practically impossible to cast, the applicable range is limited. (8) When the sand of the sand core is reused after casting, it is difficult to completely remove the coating layer and the binder because the coating layer and the binder are contained in the sand core, which requires man-hours. Then
It takes time and money. (9) The sand core has drawbacks such as difficulty in molding, easy to disintegrate, and difficult to handle, and it is difficult to satisfy the contradictory conditions of pressure resistance during casting and disintegration after casting. As described above, many steps are required, the yield is low, and it takes time and money.

That is, in order to obtain a cast product using the conventional sand core, the following steps are required. (1) Core molding → (2) Core coating mold → (3) Core drying → (4) Mold formation → (5) Casting by pouring molten metal →
(6) Sand heat treatment (sand baking) of cast product → (7) Sand removal of cast product → (8) Sand removal inspection of cast product → (9) Deburring of cast product → (10) Finished product.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems by adopting the following constitution. That is, (1) By using a special core that is difficult to break as the core,
The molding and handling of the core will be easy, the man-hours will be reduced, the time and cost will be reduced, and a casting with excellent quality will be obtained. (2) By using a special core that does not use a permeation component such as a binder, the occurrence of defects such as porosity is prevented, the occurrence of defective cast products is prevented, and the yield is improved and the productivity is improved. It contributes to the improvement and obtains high quality cast products. (3) By using a special core that has pressure resistance during casting, the occurrence of molten metal injection during casting is avoided and pressure adjustment is avoided to maintain pressure resistance (non-collapseability) and damage to the cast product. By preventing the occurrence of cast product defects such as the above, a cast product of excellent quality is obtained. (4) The use of a special core facilitates the formation of hollow parts and undercut parts, and improves core strength,
It is possible to cast all shapes and sizes regardless of shape and size, expand the range of application, and obtain castings with excellent quality. (5) By using a special core that does not require the core to be extracted from the cast product after casting, the man-hours are reduced, time and cost are reduced, and a cast product with excellent quality is obtained.

[0008]

According to the present invention, such an object is to form a mold using a metal core as a core, perform casting using the mold, and obtain a cast product after casting. To provide a casting method using a special core, characterized in that a metal core is integrated, the metal core is used as a part of a casting, and an unnecessary portion is removed to produce a casting. To be achieved.

[0009]

According to the present invention as described above, there are the following actions.

That is, according to the present invention, a casting method using a special core is used, in which a special core is used as a core to form a mold, and a casting is produced using the mold. The idea is to improve the property and expand the scope of application. (1) By using a special core that is difficult to break as the core,
Molding of the core is facilitated, molding equipment is simplified, the number of steps is reduced, time and cost are reduced, and a cast product with excellent quality can be efficiently obtained. (2) Since a special core that is hard to break is used as the core, it will not break even if dropped or thrown, making it easy to handle, easy to transport and store, and no need to adjust the pressure during casting. Is reduced, time and cost are reduced, and high-quality cast products are efficiently obtained. (3) Since the special core used does not contain a permeation component such as a binder, a molten metal is inserted, or a porosity occurs in a cast product.
Occurrence of defective cast products is prevented, yield is improved and productivity is improved, and cast products of excellent quality are efficiently obtained. (4) By using a special core as the core, it becomes easy to form the hollow part and the undercut part, and the core strength is improved. It is possible to cast a high quality product, expand the range of application, and efficiently obtain a high quality cast product. (5) By using a special core that has pressure resistance during casting, it is possible to avoid the occurrence of molten metal insertion during casting, and to avoid pressure adjustment to maintain pressure resistance (non-collapseability). By preventing the occurrence of cast product defects such as product damage, a cast product with excellent quality can be efficiently obtained. (6) Since it is not necessary to integrate the cast product and the metal core after casting to form the metal core as a part of the cast product and to remove the core from the cast product after casting, it is possible to reduce the man-hours, time and cost. To reduce castings and obtain castings of excellent quality.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the accompanying drawings.

1 to 4 show an embodiment of a casting method using the special core of the present invention.

That is, according to the present invention, a metal core is used as a core to form a mold, casting is performed using the mold, and after casting, the cast product and the metal core are integrated to form a metal core. Is a part of the cast product, and the cast product is manufactured by removing unnecessary portions, which is a casting method using a special core.

The metal core used in the present invention is
It is required to have pressure resistance (non-disintegration) during casting.

Further, the metal core is required to have a condition that does not exert a bad influence on a cast product such as generation of a large amount of gas during casting.

In this embodiment, a case where die-cast casting is performed as one of casting methods using a sheet metal core as the metal core will be described.

That is, in the case of casting a cast product using the sheet metal core, a case where the cast product is obtained by die casting will be described as one embodiment.

That is, in this embodiment, casting is performed in the following steps.

First Step First, as shown in FIG. 4, a sheet metal core 1 is formed as a metal core.

The sheet metal core 1 of the first embodiment is formed of a metal plate such as a steel plate.

As shown in FIG. 4, the sheet metal core 1 of the first embodiment has a lip groove section ( The cross-section has a horizontal C-shape.

Second Step Subsequently, as shown in FIG. 1, the sheet metal core 1 is arranged between an upper mold 2 and a lower mold 3 to form a mold 4 having a cavity 5. Form.

Further, as best shown in FIG.
By disposing the sheet metal core 1 between the upper mold 2 and the lower mold 3, a cavity portion 5 having a shape corresponding to the shape of the cast product 6 to be molded is formed inside the mold 4. ing.

Third Step Next, as best shown in FIGS. 1 and 2, a molten metal such as an aluminum molten metal is poured into the cavity 5 formed in the mold 4 depending on the material of the cast product. To do.

As a result, as shown in FIG. 2, a cast product 6 having a shape corresponding to the shape of the hollow portion 5 is formed.

In this case, the temperature of the molten metal is considerably lower than the initial temperature (for example, in the case of aluminum molten metal, about 660 ° C.) by the time it reaches the cavity 5 of the mold 4.

Further, the sheet metal core 1 is formed of a metal plate such as a steel plate and has a melting point of the molten metal which is a material of the casting 6 (for example, in the case of aluminum molten metal, about 66).
Since it has a melting point higher than 0 ° C. (for example, about 1500 ° C. for a steel plate), even if the molten metal acts, it does not melt and retains its initial shape.

The sheet metal core 1 is integrated with the casting 6 when the molten metal cools and solidifies for a predetermined time after pouring the molten metal into the cavity 5.

Subsequently, as well shown in FIGS. 2 and 3, the casting 6 formed as described above is taken out from the mold 4, thereby completing the casting.

The sheet metal core 1 contributes to the formation of a desired casting 6 by maintaining its shape during casting, and after casting, a part of the casting 6 is removed. Since this is done, post-processing such as withdrawal after casting is unnecessary.

Fourth Step Further, as well shown in FIG. 3, the casting 6 formed as described above is taken out from the mold 4, and the casting is completed. By removing the unnecessary portion of the cast product 6, a cast product 6 which is a desired finished product is formed.

After casting, the cast product 6 is formed by integrating the sheet metal core 1 with the cast product 6 without extracting the sheet metal core 1 to form a part of the cast product 6, and only the unnecessary portion is formed. Are formed by removing.

It should be noted that the sheet metal core 1 contributes to the formation of a desired casting 6 by maintaining its shape during casting, and after casting, a part of the casting 6 is Since it does not need to be extracted from the cast product 6 after casting, there is no need for post-treatment such as sand baking and sand removal in the case of the conventional sand core, which reduces man-hours, time and cost, and improves quality. An excellent cast product can be obtained.

Therefore, in comparison with the case where a casting product is obtained by casting using a sand core which is generally and widely used as a conventional core, the special core used in the casting product of the present invention is caking. It does not contain permeating components such as agents, and by covering the inner wall surface (inner wall surface of the cast product) of the hollow part, such as the hollow shape and undercut shape, with a sheet metal core, it is possible to insert a molten metal or a cast hole in the cast product. It is possible to prevent the production of defective cast products such as the occurrence of defects, improve yield, and improve productivity, and efficiently obtain cast products of excellent quality.

As a result, when the cast product 6 is manufactured by die casting using the sheet metal core 1 which is one embodiment of the casting method using the special core of the present invention, the following five steps are required. You're done. (1) Core molding → (2) Mold formation → (3) Casting by pouring molten metal → (4) Deburring of cast product → (5) Finished product.

Therefore, when performing die casting, which is one of the casting methods using the special core of the present invention, the conventional method requires the following 10 steps,
5 steps are omitted and only half of the steps are required, which can greatly reduce the number of steps.

That is, the conventional method using the sand core is as follows.
It looks like this: (1) Core molding → (2) Core coating mold → (3) Core drying → (4) Mold formation → (5) Casting by pouring molten metal →
(6) Sand heat treatment (sand baking) of cast product → (7) Sand removal of cast product → (8) Sand removal inspection of cast product → (9) Deburring of cast product → (10) Finished product.

Next, FIG. 5 shows a second embodiment of a special core used in the present invention, which is a sheet metal core 1 which is a special core.
In contrast to the sheet metal core 1 of the above-mentioned embodiment, which is integrally formed by plastic working such as press forming, it is formed into a shape divided into two by plastic working such as press forming.

This is different from the case where the sheet metal core 1 of the above-mentioned embodiment is integrally formed from the viewpoint of workability and easiness of handling. The plastic workability of the core 1 such as press forming is further enhanced.

Since the other flange portion is sandwiched between the one flange portion, the pressure resistance (non-collapseability) during casting is maintained, and the occurrence of troubles such as breakage of the cast product 6 is prevented, There is an effect that a cast product 6 of excellent quality can be obtained.

The special core used in the casting method of the present invention is not limited to the one in the above-mentioned embodiment, but various shapes using various special cores can be applied. The quality can be improved, etc., and the present invention is not limited to the above-described embodiment, and many modifications can be considered.

The casting method of the present invention is not limited to the casting method of the above-mentioned embodiment, but can be obtained by adding a specific step to further improve the quality of the cast product. The present invention is not limited to the casting method using the special core of the embodiment, and many modifications can be considered.

Further, the sheet metal core as a metal core used in the casting method of the present invention has pressure resistance during casting and gives a bad influence to a cast product such as generation of a large amount of gas during casting. The core materials satisfying this condition are as follows.

That is, examples of the material of the sheet metal core satisfying the above-mentioned conditions include a steel plate and an iron plate, which have a melting point much higher than those of aluminum and zinc which are widely used for die casting, It is possible to obtain a cast product that satisfies all the conditions and sufficiently satisfies the initial purpose.

Further, as the metal plate as the material of the sheet metal core 1 satisfying the above-mentioned conditions, a plate material made of a metal different from the above-mentioned cast product and the same metal as the cast product (that is, the same metal as the molten metal) A plate material made of, for example, aluminum and zinc, which are materials widely used for die-casting, can be mentioned, and any of the above conditions can be satisfied, and a cast product satisfying the initial purpose can be obtained. In this case, the temperature of the molten metal is considerably lower than the initial temperature (for example, in the case of aluminum molten metal, about 660 ° C.) by the time it reaches the cavity 5 of the mold 4.

Therefore, even if the sheet metal core 1 is a plate material (for example, an aluminum plate) made of the same metal as the cast product (that is, the same metal as the molten metal), it does not melt even if the molten metal acts. Retain the initial shape. Then, the sheet metal core 1 is integrated with the casting 6 when the molten metal cools and solidifies after a predetermined time has passed after pouring the molten metal into the hollow portion 5.

The metal core as the special core used in the present invention is not limited to the sheet metal core of the above-mentioned embodiment, but may be a metal core other than the plate-shaped core. As long as it has pressure resistance and does not adversely affect the cast product such as generating a large amount of gas at the time of casting, it is needless to say that a metal having a shape or material other than the above-mentioned examples can be used. The same effect as that of the embodiment can be obtained.

Further, the above embodiment is one of the cases in which a cast product is obtained by casting using a core made of a metal plate such as a steel plate as a metal core as a special core to obtain a cast product by die casting. However, the casting method using the special core of the present invention is not limited to the die casting casting, and the sand type gravity casting method, the die gravity casting method, the low pressure casting method and the precision casting method. It is needless to say that the desired cast product can be obtained by applying the present invention to other casting methods, and the same effects as those of the above-mentioned embodiment can be obtained.

Furthermore, the casting method using the special core of the present invention is not limited to the above-mentioned casting method, and it is possible to further improve the quality of the cast product by adding specific steps. The present invention is not limited to the above, and many modified examples are possible.

Next, the operation of the casting method using the special core according to this embodiment will be described.

As described above, the present invention provides a casting method using a special core in which a metal core is used as a core to form a mold, and a casting is produced using the mold. The idea is to improve the property and expand the scope of application, and has the following effects. (1) By using a special core that is not easily broken,
Molding of the core becomes easy, molding equipment is simplified, the number of steps is reduced, time and cost are reduced, and a cast product with excellent quality can be efficiently obtained. (2) Since a special core that is hard to break is used as the core, it will not break even if dropped or thrown, making it easy to handle, easy to transport and store, and no need to adjust the pressure during casting. Therefore, it is possible to efficiently obtain a high-quality cast product by reducing time and cost. (3) Since the special core used does not contain a permeation component such as a binder, a molten metal is inserted, or a porosity occurs in a cast product.
It is possible to prevent defective products from being cast, improve yield, and improve productivity, and efficiently obtain cast products with excellent quality. (4) By using a special core as the core, it becomes easy to form the hollow part and the undercut part, and the core strength is improved. Casting can be performed, the range of application can be expanded, and a high-quality cast product can be efficiently obtained. (5) By using a special core that has pressure resistance during casting, it is possible to avoid the occurrence of molten metal insertion during casting, and to avoid pressure adjustment to maintain pressure resistance (non-collapseability). It is possible to efficiently prevent the production of a cast product having excellent quality by preventing the occurrence of cast product defects such as product damage. (6) Since it is not necessary to integrate the cast product and the metal core after casting to form the metal core as a part of the cast product and to remove the core from the cast product after casting, it is possible to reduce the man-hours, time and cost. It is possible to reduce the amount of cast iron and to obtain a cast product with excellent quality.

Incidentally, the casting method using the special core of the present invention is not limited to the above-mentioned embodiments, and many modifications can be considered.

[0053]

As described above, the present invention provides a casting method using a special core for forming a mold using a metal core as a core, and manufacturing a casting using the mold. The idea is to improve productivity and expand the scope of application, and has the following excellent effects. (1) By using a special core that is not easily broken,
There are advantages that the molding of the core is facilitated, the molding equipment is simplified, the steps are reduced, the time and cost are reduced, and a cast product with excellent quality can be efficiently obtained. (2) Since a special core that is hard to break is used as the core, it will not break even if dropped or thrown, making it easy to handle, easy to transport and store, and no need to adjust the pressure during casting. Is reduced, time and cost can be reduced, and a cast product with excellent quality can be efficiently obtained. (3) Since the special core used does not contain a permeation component such as a binder, a molten metal is inserted, or a porosity occurs in a cast product.
There is an advantage that defective products of the cast product are prevented, yield is improved, productivity is improved, and a cast product having excellent quality can be efficiently obtained. (4) By using a special core as the core, it becomes easy to form the hollow part and the undercut part, and the core strength is improved. Since it is possible to cast a large amount, the range of application can be expanded, and a cast product with excellent quality can be efficiently obtained. (5) By using a special core having pressure resistance during casting, it is possible to avoid the occurrence of molten metal insertion during casting, and avoid pressure adjustment to maintain pressure resistance (non-disintegration). There is an advantage that a cast product having excellent quality can be efficiently obtained by preventing the occurrence of a cast product defect such as product damage. (6) Since it is not necessary to integrate the cast product and the metal core after casting to form the metal core as a part of the cast product and to remove the core from the cast product after casting, it is possible to reduce the man-hours, time and cost. There is an advantage that it can be reduced and a cast product with excellent quality can be obtained.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a case where a mold is formed using a sheet metal core in a casting method using a special core according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a case where a cast product is formed by pouring a molten metal in a casting method using a special core according to an embodiment of the present invention.

FIG. 3 is a cross-sectional view showing a cast product obtained by taking out from a mold in a casting method using a special core according to an embodiment of the present invention.

FIG. 4 is a sectional view showing a sheet metal core of a first embodiment used in a casting method using a special core of one embodiment according to the present invention.

FIG. 5 is a sectional view showing a second embodiment of the same sheet metal core. 1 Sheet metal core (metal core) (special core) (non-sand core) 2 Upper mold 3 Lower mold 4 Mold 5 Cavity 6 Cast product

Claims (3)

[Claims] 1. A metal core is used as a core to form a mold, casting is performed using the mold, and after the casting, the cast product and the metal core are integrated to form the cast metal product. A casting method using a special core, characterized in that a cast product is manufactured by removing unnecessary portions as a part. 2. The casting method using a special core according to claim 1, wherein a core having pressure resistance during casting is used as the metal core. 3. A casting method using a special core according to claim 1 or 2, wherein a sheet metal core is used as the metal core.