JPH0739997A - Special core for forming - Google Patents

Abstract

PURPOSE:To efficiently obtain a formed product having excellent quality and wide range shape without any restriction of the shape by using a special core except a sand core generally used as the core. CONSTITUTION:The special core 1 for forming which fills a filling material in a filling space formed in the inner part, is formed. The special core for forming is arranged between an upper mold 2 and a lower mold 3 to form a forming mold 4 and successively, a forming material is poured according to the material of the formed product 6, such as cast product, plastic formed product, ceramic formed product, into a cavity part formed in the forming mold. Successively, after forming the formed product having the shape corresponding to the shape of the cavity, the formed product is taken out from the forming mold. Unnecessary part of the flash, etc., in the formed product is removed, and the aimed formed product having excellent quality and wide range of the shape is efficiently obtd.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a special core for molding, and in particular, by using a special core without using a sand core which has been conventionally generally used as a core, Expanded selection range and enabled efficient formation of molded products in a wide range of shapes without being restricted by shape. Hollow shapes and undercut shapes etc. are cast products, plastic molded products and ceramic molded products. The present invention relates to a special molding core used for forming a molded product such as.

[0002]

2. Description of the Related Art Molding by molding methods such as casting adopted as a part of machine work, injection molding adopted as a part of plastic molding, and injection molding adopted as a part of ceramic molding In order to form a hollow portion or an undercut portion, a product has heretofore been molded using a non-disintegrating core or a disintegrating core to obtain the molded product.

By the way, as the former (non-disintegrating core), there is a metal core, which is used not only in casting but also as a molding method such as injection molding adopted as a part of plastic molding or a part of ceramic molding. However, it has a problem that it cannot be used except for those that can be directly punched or deformed, and the range of use is limited to that of a specific shape.

As the latter (disintegratable core), a sand core is generally used in casting for obtaining a cast product among the above-mentioned molded products, but it is difficult to mold and easily disintegrates. Not only is it 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, in the casting, 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. However, I could not 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 that is a component of the coating layer and the sand core after molding, it is necessary to perform a sand baking treatment to remove 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) Sand core requires complicated pressure adjustment to prevent collapse during casting, and complete collapse after casting is difficult. Therefore, heat treatment step, sand drop step, and sand drop inspection are necessary. Therefore, it requires man-hours, time and cost. (5) A defective product such as a molten product being inserted between the sand particles of the core during casting, and a defective product such as a cavity formed in the cast product due to the sand core component penetrating into the cast product are likely to occur, 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) Casting of complicated shapes and large castings are difficult or virtually impossible to cast, so the range of application is limited,
There is a problem in design and production. (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. Then
It takes time and money. (9) The sand core has many defects such as difficulty in molding, easy to collapse, and difficult to handle, and it is difficult to satisfy the conflicting conditions of pressure resistance during casting and disintegration after casting. It requires many steps as described below, the yield is low, and it takes time and cost.

That is, the conventional casting method using a sand core requires the following steps. (1) Core molding →
(2) Core coating → (3) Core drying → (4) Mold formation → (5) Casting by pouring molten metal → (6) Sand drop of cast product → (7) Sand of cast product Heat treatment (sand baking) → (8) Sand drop inspection of cast products → (9) Deburring of cast products → (10) Finished product.

[0007] Further, in the same way as the above-mentioned casting, various molded articles can be molded by a molding method such as injection molding adopted as a part of plastic molding or a molding method such as injection molding adopted as a part of ceramic molding. There was a problem.

For example, the core must be formed of a specific material having pressure resistance and heat resistance during molding, which makes core molding difficult and costly. There was a problem.

[0009]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems by adopting the following constitution.

That is, for example, in casting for obtaining a cast product among the above-mentioned molded products, (1) by using a special core, the conditions such as pressure resistance and heat resistance required for the core are alleviated. , Expand the selection range of core materials. (2) The pressure resistance and heat resistance of the core are adjusted by selecting a powdery, granular, or lumpy filling material having heat resistance to be filled inside the core and the amount thereof. (3) By using a special core that is not easily broken,
The core is easy to mold and handle, reducing man-hours and time and cost. (4) By using a special core that does not use a penetrating component such as a binder, it is possible to prevent the core component from penetrating into the cast product, thereby preventing the occurrence of defects such as porosity. , It is possible to prevent the generation of defective cast products, which contributes to the improvement of yield and the improvement of productivity. (5) By using a core that has the conflicting conditions of pressure resistance during molding and heat dissipation after molding, problems such as molten metal insertion during molding can be avoided and pressure resistance (non-collapse) The heat dissipation of the core after molding and the removal of core components are facilitated, adhesion to the molded product is prevented, and the occurrence of defects such as abrasion and damage of the molded product is prevented. To do. (6) The use of a special core facilitates the formation of hollow parts and undercut parts, and improves core strength,
Expanding the range of application by enabling casting of all shapes and sizes without being bound by shapes and sizes. (7) The special core does not contain binders and other difficult-to-remove components, making it easy to disintegrate and remove the core after casting, simplifying reuse, preventing pollution, and reducing man-hours. And save time and money.

In addition, various molding methods such as injection molding adopted as a part of plastic molding and molding methods adopted such as an injection molding adopted as part of ceramic molding can be used. The problem can be solved.

For example, by selecting a material by forming the core into a desired molded product by molding the core with a heat-resistant powdery, granular, or lumpy filling substance filled therein. Since the range can be remarkably expanded, core molding is facilitated, cost can be reduced, and the like, so that the various problems described above can be solved.

[0013]

According to the present invention, such an object is used for forming a hollow shape, an undercut shape or the like into a molded product such as a cast product, a plastic molded product or a ceramic molded product. In the molding core according to the above, the core body of the molding core is formed of a non-sand core, and a filling space is formed in the core body of the molding core, and the filling space is It is achieved by providing a special core for molding, which is filled with a heat-resistant powdery, granular, or lumpy filling material.

[0014]

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

That is, according to the present invention, by using a special core as the core, it is possible to improve the productivity and expand the range of application, and to efficiently obtain a molded product of excellent quality. , For example, in the case of a molding special core for casting to obtain a casting among the molding special cores used to form the molded product such as the above-mentioned cast product, plastic molded product or ceramic molded product, (1) Since a core is used to manufacture a molded product by using a core filled with a heat-resistant powdery, granular, or lump-like filling material, the core has heat resistance inside. Since it is sufficient to satisfy the conditions such as pressure resistance and heat resistance in the state of being filled with the substance, the conditions such as pressure resistance and heat resistance required for the core are relaxed, and the selection range of core materials is expanded. be able to. (2) The pressure resistance and heat resistance of the core can be adjusted by selecting the heat-resistant powder-like, granular, or lump-like filling material and amount to be filled inside the core. (3) By using a special core as the core, molding of the core is facilitated, molding equipment is simplified, the number of steps is reduced, and time and cost can be reduced. (4) Since a special core is used as the core, it does not break even if dropped or thrown, so handling is easy, and man-hours such as easy transportation and storage are reduced, and time and cost can be reduced. it can. (5) Since the special core used does not contain a permeation component such as a binder, the core component is prevented from permeating into the molded product, which prevents defects such as porosity from occurring. The generation of defective products can be prevented, and the yield and productivity can be improved. (6) 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 mold the ridge and expand the range of application. (7) By using a core that has the conflicting conditions of pressure resistance during molding and heat dissipation after molding, problems such as molten metal insertion during molding can be avoided and pressure resistance (non-collapse) The heat dissipation of the core after molding and the removal of core components are facilitated, adhesion to the molded product is prevented, and defects such as abrasion and damage of the molded product are prevented. Can be planned. (8) Since the special core does not contain components such as a binder that are difficult to remove and has heat dissipation after molding,
The core can be removed easily, it can be reused easily and easily, pollution can be prevented, and the man-hours can be reduced.
Time and cost can be reduced. Further, even when a molded product is obtained by a molding method such as injection molding adopted as a part of plastic molding or a molding method such as injection molding adopted as a part of ceramic molding,
By using the special molding core, a desired molded product can be obtained, and a molded product excellent in quality can be efficiently obtained.

According to the structure of the molding core, the productivity can be improved and the range of application can be expanded even in the case of plastic molding or ceramic molding.
As in the case of the above-mentioned casting, by using a special molding core, molding of the core becomes easy, molding equipment is simplified, and the number of steps is reduced, and time and cost can be reduced. In addition, handling is facilitated, transportation and storage are facilitated, and there are various effects such as reduction of man-hours such as no need for pressure adjustment during molding and reduction of time and cost.

[0017]

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 a first embodiment of a special molding core of the present invention.

That is, the present invention does not use a sand core, which is generally widely used as a core, and is generally considered to be difficult or unusable. It is a special molding core characterized by forming a hollow shape or an undercut shape into a molded product such as a cast product, a plastic molded product or a ceramic molded product by using a core.

In the present invention, a non-sand core is used as the molding special core to form a mold such as a mold, a plastic mold, or a ceramic mold, and the mold is used. A molded product is manufactured.

Further, in the present invention, the heat-resistant powdery, granular, or lumpy substance is filled inside the special molding core.

By molding using the molding die which uses a molding special core having the filling substance filled therein, a molded product such as a cast product, a plastic molded product or a ceramic molded product is molded. is there.

Therefore, the non-sand core used in the present invention is
It has pressure resistance (non-disintegrating property) when molding a molded product with the filling substance filled inside, and after the molding, it is completely removed by the residual heat of the molded product and disappears. It is required to have heat dissipation (removability).

After molding, the filling substance is removed after the core body is removed by the residual heat of the molded product,
It is required to be in an unrestrained state (free state) and have a removability for discharging and removing.

Further, the non-sand core is required to have a condition that does not adversely affect the molded product such as generation of a large amount of gas during the molding.

Here, a case where a core made of synthetic resin (plastic) is used as the non-sand core will be described.

A core (synthetic resin core or plastic core) made of synthetic resin (plastic) as a non-sand core which is the molding special core (hereinafter referred to as "resin core").
The core body H of No. 1 is made of synthetic resin (plastic).

As shown in FIG. 4, the core body H of the resin core 1 is made of synthetic resin (plastic) by a synthetic resin molding method (plastic molding method) such as injection molding. After molding the filling space S of the filling substance F into a hollow shape, the filling space S is filled with the filling substance F to form the resin core 1 which is a special molding core.

After the molding is completed, the filling substance F is removed by the residual heat of the molded product 6 and disappears, and then the unfilled state (free state) is obtained, and the filling substance F is easily discharged from the molded product 6 and removed. It is required to be able to do, but as those having this condition, powdery, granular or lumpy ones can be mentioned, which makes it easy to remove without leaving a residue,
The quality of the molded product 6 can be improved.

The filling substance F is required to have heat resistance during molding, and materials satisfying this condition include chalk (calcium carbonate), silica stone, metal and others.

Then, using the molding special core 1,
Molded products such as cast products, plastic molded products and ceramic molded products can be formed.

For example, when a molded product such as a cast product, a plastic molded product or a ceramic molded product is molded using the resin core 1 which is the molding special core, it is well shown in FIG. Thus, the resin core 1 can be disposed between the upper mold 2 and the lower mold 3 to form the molding die 4 having the cavity 5.

Thus, as shown in FIG. 1, the resin core 1 is disposed between the upper mold 2 and the lower mold 3 so that the mold 4 is molded inside. The cavity 5 having a shape corresponding to the shape of the molded product 6 to be formed can be formed.

In this embodiment, among the molding special cores used for molding various molded products such as the above-mentioned cast products, plastic molded products and ceramic molded products, the casting used for casting the cast products. The molding core will be described with reference to the molding core.

When a cast product is obtained by the casting, one of which is a special molding core as a die-casting casting core which is used when a cast product is obtained by the die-cast casting. A case where a synthetic resin core is used as the core will be described.

Here, the case of performing die casting, which is one of the molding methods using the special molding core of the present invention, will be described.

First, although not shown, one end is opened and a filling space S is formed into a hollow shape by using a synthetic resin (plastic) by a synthetic resin molding method (plastic molding method) such as injection molding. After molding the formed core body H, the filling space S is filled with a heat-resistant filling material F such as powder, granules, or lumps, and the opening is closed, as shown in FIG. As described above, the resin core 1 in which the filling material F is filled in the filling space S is formed.

Subsequently, as well shown in FIG. 1, the resin core 1 is disposed between the upper mold 2 and the lower mold 3,
A mold 4 having a cavity 5 having a shape corresponding to the shape of the cast product 6 to be molded is formed.

Next, as well shown in FIGS. 1 and 2, by using the resin core 1 in which the filling space S is filled with the filling substance F, the pressure resistance when pouring the molten metal is improved. Hold,
It is possible to prevent deformation and maintain the original shape, and improve the heat resistance when pouring the molten metal to contribute to casting.

1 and 2, the cavity 5 formed in the mold 4 using the resin core 1 is filled with aluminum molten metal or the like depending on the material of the cast product. By pouring the molten metal while applying pressure, the cavity 5
The cast product 6 having a shape corresponding to the shape of is cast and formed.

Next, after the casting is finished, the casting 6 formed as described above is taken out from the mold 4, and the filling substance F is discharged from the casting 6 and removed, whereby the casting is finished.

At this time, in the resin core 1, since the core body H excluding the filling substance F is completely removed and disappeared by the residual heat of the casting 6, only the filling substance F remains. It becomes easier to discharge F from the cast product 6,
Therefore, the resin core 1 can be completely removed.

Therefore, defects such as wear and breakage of the product can be prevented, the quality of the cast product can be improved, the yield can be improved, and time and cost can be saved. It becomes possible to improve the sex.

Further, as best shown in FIG.
The casting product 6 formed as described above is taken out from the casting mold 4, and after the core body H is removed and eliminated by residual heat, the remaining filling material F is easily discharged from the casting product 6, thereby Since the casting is completed by completely removing the resin core 1, unnecessary portions such as burrs of the cast product 6 are removed, and the cast product 6 as a desired end product is formed.

The cast product 6 thus formed has excellent appearance quality and functional quality because defects such as cavities are prevented from occurring.

Therefore, as compared with the case where a casting product is obtained by casting using a sand core which is generally widely used as a conventional core, the man-hours are significantly reduced, and a casting product of excellent quality is efficiently produced. You will get better.

As a result, the resin core 1 contributes to the formation of the desired casting 6 by maintaining its shape during casting, and the residual heat of the casting 6 is exerted after casting. The core body H excluding the filling substance F is melted and completely removed and disappeared. Further, the filling substance F is in an unrestrained state (free state in a state where the core body H is dissolved and removed and disappeared after casting is completed. ), It can be easily discharged and removed from the cast product 6, and can be completely removed without leaving any residue, so that no residue remains.

Therefore, the non-sand core used in the present invention is
At the time of molding, in which a molded product is molded with the filling substance F filled therein, pressure resistance (non-disintegration) is provided, and after molding, the filling substance F is removed and eliminated by residual heat of the molded product. It is required to have heat dissipation (removability).

That is, the resin core 1 is one in which the filling space S inside is filled with the heat-resistant filling material F, and the specific heat becomes large as compared with the case where only the synthetic resin (plastic) is used, Since the heat capacity becomes large, the temperature rise of the resin core 1 when pouring the molten metal becomes relatively small,
Since the heat resistance to the molten metal is remarkably improved and the pressure resistance is also remarkably improved, the initial shape can be maintained without thermal deformation or pressure deformation even when the high-pressure molten metal is poured during molding.

At this time, 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, Due to the temperature and heat capacity of the resin core 1, even if the molten metal acts, the resin core 1 can maintain the initial shape without immediate melting due to the reflecting action and the temperature action.

After the molten metal is poured into the hollow portion 5, the resin core 1 is cooled and solidified for a predetermined time, and then the filling material F is filled with the residual heat of the cast product 6. The core body H is removed by melting except.

The filling material F can be easily discharged from the casting 6 and completely removed after the casting is completed.

Therefore, by casting the resin core 1 without deforming it while maintaining the original shape, a cast product 6 having a shape corresponding to the shape of the cavity 5 can be obtained.

As described above, by using the resin core 1 of the present invention in which the filling substance S is filled in the filling space S, the pressure resistance when pouring the molten metal is maintained, deformation is prevented, and The shape can be maintained, and the heat resistance when pouring the molten metal can be improved to contribute to casting.

The resin core 1 according to the present embodiment is molded by molding the molded product 6 with the filling substance F filled therein.
In addition to having pressure resistance (non-disintegration property), it is required to have heat extinction property (removability) which is removed and eliminated by the residual heat of the molded product after the molding, except for the filling substance F. Synthetic resins (plastics) and other materials can be cited as core materials that satisfy the conditions. Among these, synthetic resins (plastics) include the following.

That is, as a synthetic resin (plastic) as a core material having all of the above conditions, for example,
There is a thermoplastic synthetic resin, which satisfies all of the above conditions, and a cast product that sufficiently satisfies the initial purpose can be obtained.

The most suitable of these thermoplastic synthetic resins are fluororesins (polyfluorethylene resins) such as tetrafluoroethylene resin, polyimide resins, polyamideimide resins and polysulfone resins, and any one of the above conditions is satisfied. Also, it is possible to obtain a cast product that satisfies the initial purpose.

Next to this, there are polyamide resin (nylon resin) and polypropylene resin, which satisfy all of the above conditions, and a cast product satisfying the initial purpose can be obtained.

Other examples include polyethylene resin and polyester resin (Tetoron resin), which have all of the above conditions, and a cast product satisfying the initial purpose can be obtained.

Further, as the core made of synthetic resin (plastic) used for the special core for casting of this embodiment,
The molded product 6 is not limited to the above synthetic resin (plastic) and has pressure resistance (non-disintegration) at the time of molding for molding the molded product 6 in a state in which the filling substance F is filled therein. The core body H excluding the filling material F is removed by the residual heat and disappears (removability), and does not adversely affect the cast product such as generating a large amount of gas during casting. If so, it goes without saying that a synthetic resin (plastic) other than the above-mentioned examples can be used, and the same effect as that of the above-mentioned examples can be obtained.

Next, FIG. 5 shows a second embodiment of the molding special core of the present invention, and the molding special core made of rubber (hereinafter referred to as "rubber core") will be described.

That is, the core body H of the rubber core 1 which is the molding special core is made of heat-resistant synthetic rubber, silicon rubber, fluorine rubber or the like and is well shown in FIG. As described above, the rubber core 1 which is a special molding core is formed by molding the filling space S of the filling substance F into a hollow shape formed inside and then filling the filling space S with the filling substance F. To do.

As shown in FIG. 1, the rubber core 1 is disposed between the upper mold 2 and the lower mold 3 to form a mold 4 having a cavity 5. You can

As shown in FIG. 1, the rubber core 1 is arranged between the upper mold 2 and the lower mold 3,
After forming the mold 4 having the cavity 5, as shown in FIGS. 1 and 2, the cavity 5 formed in the mold 4 has a molten metal such as an aluminum melt depending on the material of the casting. By pouring the molten metal, a cast product 6 having a shape corresponding to the shape of the hollow portion 5 is cast in a state where the rubber core 1 maintains its original shape without being deformed.

Subsequently, as well shown in FIGS. 2 and 3, the casting 6 formed as described above is taken out from the mold 4, whereby the casting is completed and burrs and the like of the casting 6 are removed. The unnecessary portion is removed to form a casting 6 as a desired finished product.

The cast product 6 thus formed is a cast product having excellent appearance quality and functional quality in which defects such as cavities are prevented from occurring.

Therefore, by casting using a sand core which is generally widely used as a conventional core, the man-hours are greatly reduced as compared with the case of obtaining a cast product, and a cast product of excellent quality is obtained. You will be able to obtain it efficiently.

In this case, since the temperature of the molten metal is considerably lower than the initial temperature by the time it reaches the cavity 5 of the mold 4, the rubber core 1 is heat-resistant in the filling space S inside. It is filled with a certain filling material F, and has a larger specific heat and a larger heat capacity than the case where it is made of only rubber, so that the temperature rise of the rubber core 1 when pouring the molten metal is relatively small. Since the heat resistance to the molten metal is remarkably improved and the pressure resistance is remarkably improved, the initial shape can be maintained without thermal deformation or pressure deformation even when the high-pressure molten metal is poured during molding.

The special molding core of the present invention is not limited to the materials and shapes of the above-mentioned embodiments, but can be applied to various shapes using various materials, and the quality of molded products can be improved. You can

That is, the material of the molding special core of the present invention is not limited to the resin core, the rubber core such as the natural rubber or the synthetic rubber shown in the above-mentioned embodiment, and the core has a heat resistance. A molded product is manufactured by using a powdery, granular, or lumped filling substance that has a pressure resistance (non-disintegration) at the time of molding the molded product, and molding Any core that has heat-dissipating property (removability) that can be removed and lost by residual heat of the molded product afterwards, such as tin, lead,
In addition to low melting metals such as antimony, ceramics and other single materials, it is possible to use FRR (fiber reinforced rubber), FRP (fiber reinforced plastic), GFRP (glass fiber reinforced plastic) and other composite materials. It is possible to use special molding cores made of various materials, and it is possible to obtain the same effects as those of the above-described embodiments.

That is, the molding special core used in the present invention is not limited to the materials and shapes of the above-mentioned examples, but can be applied to various shapes using various materials, and cast products In addition to the resin cores and rubber cores shown in the above-mentioned examples, those having a heat resistant powdery, granular, or lumpy filling substance can be used. By using, by producing a molded article, it is sufficient if the core has a reciprocal condition of pressure resistance during molding and heat dissipation after molding, and many variations are conceivable. Similar effects can be obtained.

Further, the special molding core of the present invention is not limited to die casting as one of the casting methods shown in the above-mentioned embodiment, and a specific step is added to the die casting method to further cast a product. The quality can be improved and the like is not limited to the above-described embodiment, and many modifications can be considered.

Further, in the above embodiment, the case of performing die casting as one of the casting methods has been described.
The molding special core of the present invention is not limited to the die casting, and is a cast product cast by a sand type gravity casting method, a die gravity casting method, a low pressure casting method, a precision casting method, or another casting method. Of course, the same excellent effects as those of the above-mentioned embodiment can be obtained.

In this case, the effect of the present invention is particularly great in the gravity casting method.

That is, in the gravity casting method, the residence time of the molten metal during casting is longer than that of other casting methods, the time in which the molten metal contacts the core is long, and the temperature of the molten metal is relatively high. In particular, the core is required to have pressure resistance and heat resistance, but using the molding special core 1 described above, a filling material having heat resistance inside the core, such as powder, granules or lumps, is used. By molding a molded product using the one filled with, the specific heat becomes larger and the heat capacity becomes larger than the case where a resin core made of only synthetic resin (plastic) is used. When the molten metal is poured, the temperature rise of the resin core 1 becomes relatively small, the heat resistance to the molten metal is significantly improved, and the pressure resistance is also significantly improved. Therefore, the molten metal with a long residence time during casting is poured. The initial shape without thermal deformation or pressure deformation Can hold, it is a contribute to the formation of the casting 6 in intended purpose.

At this time, referring to FIGS. 1 to 4, the special molding core will be described with respect to the special molding core used in the gravity casting method which is the third embodiment of the special molding core of the present invention.

That is, in the present embodiment, when a casting product is obtained by the gravity casting method using a casting special core as a molding special core, one of them is the casting special core. The case of using a synthetic resin core will be described.

First, the core body H of the resin core 1 is made of synthetic resin (plastic) as shown in FIG. 4 by a synthetic resin molding method (plastic molding method) such as injection molding. Then, the filling space S of the filling material F is formed into a hollow shape inside, and then the filling material F is filled to form the resin core 1 which is a special molding core.

Using the resin core 1 which is the molding special core 1, a cast product can be formed by the gravity casting method.

For example, as best shown in FIG.
The resin core 1 is arranged between the upper mold 2 and the lower mold 3 to form a mold 4 having a cavity 5.

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.

As a result, in the resin core 1, the filling space S inside the core is filled with the heat-resistant filling material F in the form of powder, particles, or lumps, and the synthetic resin (plastic) is used.
Compared to the case of using a resin core made of only, the specific heat becomes large and the heat capacity becomes large, so the temperature rise of the resin core 1 when pouring the molten metal becomes relatively small, and the heat resistance to the molten metal In addition to significantly improving the pressure resistance, the initial shape can be maintained without thermal deformation or pressure deformation even when pouring a molten metal with a long residence time during casting. It can contribute to the formation of the target casting 6.

The temperature of the molten metal is considerably lower than the initial temperature (for example, about 750 ° C. in the case of aluminum molten metal) by the time it reaches the cavity 5 of the mold 4, so that Due to the temperature and heat capacity of the resin core 1, even if the molten metal acts, the resin core 1 can maintain the initial shape without immediate melting due to the reflecting action and the temperature action.

Therefore, it is possible to obtain a cast product 6 having a shape corresponding to the shape of the hollow portion 5 while maintaining the original shape without deforming the resin core 1.

Next, after the casting is completed, the cast product 6 formed as described above is taken out from the mold 4, and in a state where the core body H is melted and removed, the unconstrained state (free state) is obtained. The casting is completed by discharging the filled filling material F from the casting 6 and completely removing it.

Further, as best shown in FIG.
By removing the cast product 6 formed as described above from the mold 4 and removing the resin core 1 as described above, the casting is completed, so that unnecessary parts such as burrs of the cast product 6 are removed, A cast product 6 which is a desired finished product is formed.

The cast product 6 thus formed is a cast product in which the occurrence of defects such as cavities is prevented and the appearance quality and functional quality are excellent.

Therefore, by casting using a sand core which is generally widely used as a conventional core, the man-hours are greatly reduced as compared with the case where a cast product is obtained, and a cast product of excellent quality is obtained. You will be able to obtain it efficiently.

As described above, even in the gravity casting method, the special molding core 1 retains its shape during casting, thereby contributing to the formation of the intended casting 6 and, after casting, The core body H was melted and completely removed by the residual heat of the cast product 6, and the core body H was completely dissolved and removed after the casting was completed. In this state, it can be easily discharged from the cast product 6 and completely removed. Therefore, it is easy to completely remove the residual amount and prevent defects such as wear and damage of the product. It is possible to improve the yield, improve the yield, save time and cost, and improve the productivity.

Even when the special casting core is used as the molding special core as one of the embodiments of the present invention, the die casting casting method and the gravity casting method of each of the above embodiments However, the present invention is not limited to the above, and can be applied to a low pressure casting method, a precision casting method, and other casting methods. Many modifications are conceivable, and the same effects as those of the above-described embodiment can be obtained.

Next, the operation of the special molding core according to this embodiment will be described.

That is, according to the present invention, by using a special molding core as the core, it is possible to improve the productivity and expand the range of application, and to efficiently obtain a molded product of excellent quality. For example, in the case of a molding special core for casting, which is used to form a molded product such as a cast product, a plastic molded product, a ceramic molded product, etc. , Has the following effects. (1) Since a core is used to manufacture a molded product by using a core filled with a heat-resistant powdery, granular, or lump-like filling material, the core has heat resistance inside. Since it is sufficient to satisfy the conditions such as pressure resistance and heat resistance in the state of being filled with the substance, the conditions such as pressure resistance and heat resistance required for the core are relaxed, and the selection range of core materials is expanded. be able to. (2) The pressure resistance and heat resistance of the core can be adjusted by selecting the heat-resistant powder-like, granular, or lump-like filling material and amount to be filled inside the core. (3) By using a special molding core as the core, molding of the core is facilitated, molding equipment is simplified, the number of steps is reduced, and time and cost can be reduced. (4) Since a special molding core is used as the core, it does not break even if dropped or thrown, so handling is easy, and man-hours are reduced, such as easier transportation and storage, and time and cost are reduced. be able to. (5) Since the molding special core to be used does not contain a permeation component such as a binder, the core component is prevented from permeating into the molded product, so that the occurrence of defects such as porosity is prevented. In addition, it is possible to prevent defective products from being formed and to improve yield and productivity. (6) By using a special molding core as the core, it becomes easy to form a hollow portion or an undercut portion,
Moreover, since the strength of the core is improved, it is possible to mold all shapes and sizes without being restricted by the shape and size, and it is possible to expand the range of application. (7) By using a core that has the conflicting conditions of pressure resistance during molding and heat dissipation after molding, problems such as molten metal insertion during molding can be avoided and pressure resistance (non-collapse) The heat dissipation of the core after molding and the easy removal of core components are prevented, and the adhesion to the molded product is prevented, and the occurrence of molded product defects such as wear and damage of the molded product is prevented. Can be achieved. (8) The special molding core does not contain components that are difficult to remove, such as a binder, and has heat dissipation properties after molding, so it is easy to completely remove the core and prevent pollution. In addition to the above, the number of steps can be reduced, and the time and cost can be reduced.

The molding special core of the present invention is not limited to the above-mentioned embodiments, and many modifications can be considered.

That is, the special core for molding of the present invention is not limited to the case of obtaining a cast product by the casting shown in each of the above-mentioned examples, and can be applied to a molded product formed by a molding method other than the casting. You can

For example, the special molding core of the present invention can be used in various molding methods such as plastic molding and ceramic molding, which are molding methods other than the above-mentioned casting, to obtain plastic molded articles and ceramic molded articles of excellent quality. Various molded products such as molded products can be efficiently obtained, and at the same time, productivity can be improved and the range of application can be increased, and the cost of molded products can be significantly reduced.

The present invention uses a molding special core as a core, forms a molding die such as a plastic molding die or a ceramic molding die, and forms a hollow portion inside the molding special core. In addition, various moldings such as plastic moldings and ceramic moldings can be molded by using the molding die while continuously flowing a fluid such as gas or liquid.

During molding, the special molding core contributes to the formation of a desired molded product by maintaining its shape, and after molding, the filling material is filled by the residual heat of the molded product. Except for F, the core body H is dissolved and completely removed and disappeared. Further, the filling substance F can be easily discharged and completely removed from the molded product 6 after the completion of molding, so that a residual component remains. Without the need for complete removal, it is possible to prevent defects such as product wear and damage, improve the quality of molded products, and improve the yield.
Furthermore, time and cost can be saved and productivity can be improved.

Further, the special molding core of the present invention is not limited to the case obtained by the above-mentioned molding methods,
It is possible to further improve the quality of the molded product by adding a specific step, and the present invention is not limited to the case obtained by the above-mentioned molding method, and many modified examples are possible.

Even when the special molding core of the present invention is used in various molding methods such as plastic molding and ceramic molding, which are molding methods other than the above-mentioned casting, the materials and shapes of the above-mentioned examples are used. The present invention is not limited to those described above, but can be applied to various shapes using composite materials and other materials other than those in the above-mentioned respective examples, and the quality of molded products can be improved.

That is, the material of the molding special core of the present invention is not limited to the resin core or the rubber core shown in the above-mentioned embodiment, but may be powdery, granular or lump-shaped having heat resistance inside the core. By using a material filled with a filling material such as, by producing a molded article, it is sufficient if it is a core that has both conflicting conditions of pressure resistance during molding and heat dissipation after molding,
Low melting metals such as tin, lead and antimony, ceramics and other single materials can be used, as well as FRR (fiber reinforced rubber), FRP (fiber reinforced plastic) and GFRP.
(Glass fiber reinforced plastic) Other composite materials can be used, and special molding cores using various materials are conceivable, and the same effects as those of the above-described embodiments can be obtained.

The special molding core of the present invention is applied to various molding methods such as injection molding adopted as part of plastic molding and injection molding adopted as part of ceramic molding. Even in such a case, as in the case of the casting special core used for the casting, it has an excellent action, and the conventional problems can be solved.

That is, according to the molding special core of the present invention, molding is carried out by using a material having a heat-resistant filling material such as powder, granules or lumps filled therein, By maintaining its shape, it contributes to the formation of a desired molded product, and after molding, the core material H is completely melted by removing the filling substance F by the residual heat of the molded product. Further, the filling substance F can be easily discharged and completely removed from the molded product 6 after the molding is completed, so that the special core 1 can be easily completely removed from the molded product 6 without leaving any residue. It is possible to significantly expand the range of material selection, facilitate core molding, reduce costs, and prevent defects such as wear and damage of products, improving the quality of molded products. And improve the yield, You can save between the expense, so that it is possible to improve the productivity.

[0103]

INDUSTRIAL APPLICABILITY As described above, according to the present invention, by using the non-sand core as the molding special core as the core, the productivity is improved and the applicable range is expanded, and the molding having excellent quality is achieved. The idea is to obtain a cast product, for example, to obtain a cast product among the special molding cores used for forming a cast product, a plastic molded product, a ceramic molded product, or the like. In the case of a special molding core, there are the following excellent effects. (1) Since a core is used to manufacture a molded product by using a core filled with a heat-resistant powdery, granular, or lump-like filling material, the core has heat resistance inside. Since it is sufficient to satisfy the conditions such as pressure resistance and heat resistance in the state of being filled with the substance, the conditions such as pressure resistance and heat resistance required for the core are relaxed, and the selection range of core materials is expanded. There is an advantage that can be. (2) There is an advantage that the pressure resistance and heat resistance of the core can be adjusted by selecting a powdery, granular, or lumpy filling material and amount having heat resistance to be filled inside the core. . (3) The use of a special molding core as the core facilitates molding of the core, simplifies molding equipment, reduces the number of steps, and has the advantage of reducing time and cost. is there. (4) Since a special molding core is used as the core, it does not break even if dropped or thrown, so handling is easy, and man-hours are reduced, such as easier transportation and storage, and time and cost are reduced. There is an advantage that can be. (5) Since the molding special core to be used does not contain a permeation component such as a binder, the core component is prevented from permeating into the molded product, so that the occurrence of defects such as porosity is prevented. In addition, there is an advantage that defective products of molded products can be prevented, yield can be improved, and productivity can be improved. (6) By using a special molding core as the core, it becomes easy to form a hollow portion or an undercut portion,
Moreover, since the strength of the core is improved, there is an advantage that it is possible to mold all shapes and sizes without being restricted by the shape and size, and to expand the applicable range. (7) By using a core that has the conflicting conditions of pressure resistance during molding and heat dissipation after molding, problems such as molten metal insertion during molding can be avoided and pressure resistance (non-disintegration) The heat dissipation of the core after molding and the easy removal of core components are prevented, and the adhesion to the molded product is prevented, and the occurrence of molded product defects such as wear and damage of the molded product is prevented. There is an advantage that can be achieved. (8) The special molding core does not contain components that are difficult to remove, such as a binder, and has heat dissipation properties after molding, so it is easy to completely remove the core and prevent pollution. In addition to the advantages, the man-hours can be reduced, and the time and cost can be reduced.

Further, even when a molded product is obtained by a molding method such as injection molding adopted as a part of plastic molding or a molding method such as injection molding adopted as a part of ceramic molding, the molding special product of the present invention is used. By using the core, there is an advantage that a desired molded product having excellent quality can be efficiently obtained.

The productivity can be improved and the range of application can be increased. By using the special molding core, molding of the core can be facilitated, molding equipment can be simplified, and the number of steps can be reduced. The time and cost can be reduced, handling is easy, transportation and storage are easy, and pressure adjustment at the time of molding is not required.
There are various excellent advantages such as reduction of time and cost.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a method for forming a molding die using a resin core of a molding special core according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a method for molding a molded product by injecting a molding material in a special molding core according to one embodiment of the present invention.

FIG. 3 is a cross-sectional view showing a molded product taken out from a molding die in a special molding core according to one embodiment of the present invention.

FIG. 4 is a sectional view showing a first embodiment of a special molding core of the present invention.

FIG. 5 is a cross-sectional view showing a second embodiment of the special molding core.

[Explanation of symbols]

1 Special core for molding (non-sand core) (resin core) (rubber core) 2 Upper mold 3 Lower mold 4 Mold (plastic mold) (ceramic mold) 5 Cavity 6 Molded product (Casting product) (Plastic molding product) (Ceramic molding product) H Core body F Filling material S Filling space

Claims (7)

[Claims] 1. A molding core used for forming a hollow shape, an undercut shape, or the like into a molded product such as a cast product, a plastic molded product, a ceramic molded product, and the like. The core body is formed from a non-sand core, and a filling space is formed in the core body of the molding core, and the filling space is filled with a heat-resistant packing material such as powder, granules, or lumps. Special core for molding characterized by being filled. 2. The molding special according to claim 1, wherein a core body having a reciprocal condition of pressure resistance during molding and heat dissipation after molding is used as the non-sand core. Core. 3. The special molding core according to claim 1 or 2, wherein a core body made of synthetic resin (plastic) is used as the non-sand core. 4. The molding special core according to claim 1 or 2, wherein a core body made of rubber is used as the non-sand core. 5. The molding special core according to claim 1, wherein the filling substance is black ink (calcium carbonate). 6. The molding special core according to any one of claims 1 to 4, wherein the filling material is made of silica stone. 7. The molding special core according to any one of claims 1 to 4, wherein the filling substance is made of metal.