JPH071080A - Special molding core - Google Patents

Abstract

PURPOSE:To efficiently obtain a molded product having excellent quality and comprehensive shape without being restricted by the shape by using a special core other than a sand core generally used as the core. CONSTITUTION:The special molding core 1 being non-sand core is formed by using a synthetic resin, etc. The special molding core 1 is arranged between an upper die 2 and a lower die 3 to form a forming die 4. Then a molding material such as molten aluminum, synthetic resin (plastic) material, ceramic material is poured into a cavity part 5 formed in the molding die 4 in accordance with the material of a molded product 6. Successively, after molding the molded product 6 corresponding to the shape of the cavity part, the molded product 6 is taken out from the molding die 4. By removing the unnecessary part such as casting flash in the molded product 6, the molded product having excellent quality and comprehensive shape can efficiently be 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) 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) 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 mold → (3) Core drying → (4) Mold formation → (5) Casting by pouring molten metal →
(6) Casting sand removal → (7) Casting sand heat treatment (sand baking) → (8) Casting sand removal inspection → (9) Casting deburring → (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) By using a special core, the pressure resistance and heat resistance of the core are adjusted by selecting the material 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 easier to disintegrate and remove the core after casting, preventing pollution, and reducing man-hours, saving time and money. Reduce.

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 above-mentioned special core for molding is used. By using, the intended molded product can be obtained, and a molded product having excellent 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 to easy handling, easy transportation and storage, pressure adjustment at the time of molding is not required, and man-hours are reduced, and time and cost can be reduced. You can

[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. It is achieved by providing a special molding core, characterized in that the molding core is formed from a non-sand core.

[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) By using a special core, conditions such as pressure resistance and heat resistance required for the core can be relaxed, and the selection range of the core material can be expanded. (2) By using a special core, the pressure resistance and heat resistance of the core can be adjusted by selecting the material and the amount thereof. (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 easily removed, the occurrence of pollution can be prevented, 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 above-mentioned molding special core is used. By using, the intended molded product can be obtained, and a molded product having excellent 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.

[0018]

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 molding die such as a mold, a plastic molding die or a ceramic molding die, and the molding die is used. A molded product is manufactured.

Then, a molded product such as a cast product, a plastic molded product or a ceramic molded product is molded by molding using the molding die using the special molding core.

Therefore, the non-sand core used in the present invention is
When molding a molded product, it is required to have pressure resistance (non-disintegration property) and heat dissipation property (removability) to be removed and removed by residual heat of the molded product after molding.

Further, the non-sand core is required to have a condition that does not exert a bad influence on a molded product such as generation of a large amount of gas at the time of 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").
1 is made of synthetic resin (plastic).

The resin core 1 is made of a synthetic resin (plastic) by a synthetic resin molding method (plastic molding method) such as injection molding, as shown in FIG. To have a hollow shape.

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 special molding 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.

In this way, as shown in FIG. 1, by disposing the resin core 1 between the upper die 2 and the lower die 3, the inside of the molding die 4 is The hollow portion 5 having a shape corresponding to the shape of the molded product 6 to be molded can be formed.

In the present embodiment, of the special molding cores used for molding various molded products such as the above-mentioned cast products, plastic molded products, ceramic molded products, etc., they are used to cast the cast products first. Regarding the casting core, a special molding core will be described.

When a cast product is obtained by the casting, and one of them is a special molding core which is used as a die casting core for use in obtaining the cast product by die casting, a non-sand The case of a synthetic resin core 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 illustration is omitted, in the same manner as described above, a resin core 1 having a hollow portion S is formed using a synthetic resin (plastic).

A cast product can be cast using the resin core 1.

For example, as best shown in FIG.
The resin core 1 is disposed between the upper mold 2 and the lower mold 3 to form a mold 4 having a cavity 5 having a shape corresponding to the shape of the cast product 6 to be molded.

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

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 completely removed, whereby the casting is finished.

At this time, the resin core 1 is removed and lost by the residual heat of the cast product 6, so that the resin core 1 can be removed from the cast product 6.

As described above, the resin core 1 is
By maintaining its shape, the intended casting 6
In addition to contributing to the formation of the above, and after the casting, the cast product 6 is melted and removed by the residual heat of the cast product 6, so that it is possible to remove without leaving a residue.

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 the time and cost can be saved. It becomes possible to improve the sex.

Further, as best shown in FIG.
The casting 6 formed as described above is taken out from the mold 4, the resin core 1 is removed and lost by residual heat, and the casting is completed by easily removing the resin core 1 from the casting 6, so that the casting Remove unnecessary parts such as burrs of item 6,
A cast product 6 which is a desired finished 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, 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 greatly reduced, and a casting product of excellent quality is efficiently produced. You will get better.

As described above, when die casting is performed using the die casting core which is the first embodiment of the molding special core of the present invention, the resin core 1 has a shape which is obtained during casting. By holding the alloy, it contributes to the formation of the intended casting 6 and, after casting, is melted and removed by the residual heat of the casting 6 and can be completely removed without leaving a residue. As a result, no residue remains in the cast product 6, and it is possible to prevent defects such as wear and damage of the product, improve the yield, and save time and cost, thus improving productivity. Can be improved.

Therefore, the non-sand core used in the present invention is
When molding a molded product, it is required to have pressure resistance (non-disintegration property) and heat dissipation property (removability) to be removed and removed by residual heat of the molded product after molding.

By casting the resin core 1 in its original shape without deforming it, a cast product 6 having a shape corresponding to the shape of the cavity 5 can be obtained.

At this time, the temperature of the molten metal is considerably lower than the initial temperature (for example, about 660 ° C. in the case of aluminum molten metal) 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.

Further, the resin core 1 is melted and removed by the residual heat of the casting 6 after the molten metal has cooled and solidified for a predetermined time after pouring the molten metal into the hollow portion 5. Of.

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

Therefore, in the case of performing die casting, which is one of the casting methods using the non-sand core as the special core of the present invention, the conventional method requires the following 10 steps. In comparison, only 4 steps are required and 6 steps are omitted.

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) Casting sand removal → (7) Casting sand heat treatment (sand baking) → (8) Casting sand removal inspection → (9) Casting deburring → (10) Finished product.

By casting using a sand core which is generally widely used as a conventional core, the man-hours are significantly 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.

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, but a specific step is added to the die casting method to obtain a cast product. The quality can be improved and the like is not limited to the above-described embodiment, and many modifications can be considered.

In the above embodiment, the case of performing die casting as one of the casting methods has been described. However, the molding special core of the present invention is not limited to the die casting, and the sand gravity casting method is also applicable. Of course, the present invention can be applied to a casting product cast by a die gravity casting method, a low pressure casting method, a precision casting method, or another casting method, and it is possible to obtain the same excellent effects as those of the above-mentioned embodiment. .

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 during 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 when the molding special core 1 is used, the heat capacity is large, and the molding special core when pouring molten metal is used. The temperature rise of the child 1 is relatively small, the heat resistance to the molten metal is high, and the pressure resistance is also high. Therefore, even when the molten metal having a long residence time during casting is poured, the initial shape is not deformed. Can be held, and it can contribute to the formation of the desired casting product 6.

Even in this case, the resin core 1 has pressure resistance (non-disintegration) at the time of casting for casting, and after the casting, the resin core 1 is removed and lost by the residual heat of the casting. Since it has heat dissipation properties (removability) and conditions that do not adversely affect the cast product, such as generating a large amount of gas during casting, it is possible to efficiently obtain a cast product with excellent quality. Can contribute to that.

A cast product can be formed by using the resin core 1 which is the molding special core.

In this case, the resin core 1 is attached to the upper die 2 and the lower die 3
After forming the mold 4 having the cavity portion 5 by disposing the molding material in the cavity portion 5 formed in the mold 4 in the same manner as in the above-described embodiment. Thus, the desired molded product 6 can be molded.

In this case, 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, so that the resin core 1 has improved pressure resistance. Due to its own temperature and heat capacity, the temperature rise of the resin core 1 when pouring the molten metal is relatively small, the heat resistance to the molten metal is high, and the pressure resistance is also improved. Even when the molten metal is poured, the initial shape can be maintained without thermal deformation or pressure deformation such as immediate melting due to the reflection effect and the temperature effect.

The molding core of the present invention is not limited to the casting method of the above-mentioned embodiment, and many modifications are conceivable. Furthermore, it is a part of plastic molding which is a molding method other than the casting method. It can be applied to the molding cores used in molding methods such as injection molding that is adopted as the above and molding methods such as injection molding that is adopted as a part of ceramic molding, and solves various problems as in the case of the above casting. can do.

The molding special core contributes to the formation of a desired molded product by maintaining its shape during molding, and is melted by residual heat of the molded product after molding. Are removed and eliminated, leaving no residual residue, making it easier to remove and discharge, and prevent defects such as product wear and damage, improving the quality of castings, improving yield, and further improving time. Therefore, the cost can be saved and the productivity can be improved.

Further, the special molding core of the present invention is not limited to the case obtained by each of 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.

Next, referring to FIGS. 1 to 4, injection molding and ceramics which are adopted as a part of plastic molding which is a molding method other than the casting method which is the second embodiment of the molding special core of the present invention. A description will be given of a special molding core applied to a molding core used for injection molding adopted as a part of molding.

That is, in the present embodiment, when a molded product is obtained by injection molding using the resin core 1 as the molding special core, one of them is the resin core as the molding special core. The case of using the child 1 will be described.

First, although illustration is omitted, a resin core 1 having a hollow portion S is made of synthetic resin (plastic) in the same manner as in the above embodiment, as shown in FIG.
To form.

By using the resin core 1 which is the molding special core 1, a molded product such as a plastic molded product or a ceramic molded product can be formed.

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 molding die 4 having a cavity 5 having a shape corresponding to the shape of the molded product 6 to be molded.

Next, as best shown in FIGS. 1 and 2, the cavity 5 formed in the molding die 4 using the resin core 1 is synthesized in accordance with the material of the molded product. By injecting a molding material such as resin (plastic) or ceramic while applying pressure, a molded product 6 having a shape corresponding to the shape of the cavity 5 is injection molded.

At this time, since the resin core 1 has a large specific heat and a large heat capacity, a synthetic resin (plastic) is used.
The temperature rise during injection of molding materials such as ceramics and ceramics is relatively small, heat resistance is significantly improved, and pressure resistance is also significantly improved.
The initial shape can be maintained without thermal deformation or pressure deformation, and it can contribute to the formation of the intended molded product 6.

Further, the temperature at the time of injecting the molding material is considerably lower than the initial temperature by the time it reaches the cavity 5 of the molding die 4, so that the resin core 1 has its own temperature. With the heat capacity, the initial shape can be maintained without immediate melting due to the reflection effect and the temperature effect even when the high temperature acts.

Therefore, the molded product 6 having a shape corresponding to the shape of the hollow portion 5 can be obtained while maintaining the original shape without deforming the resin core 1.

Next, after the molding is completed, the molded product 6 formed as described above is taken out from the molding die 4.

At this time, the resin core 1 is the molded product 6
The remaining heat dissipates the heat, so that it can be easily removed from the molded product 6.

As described above, the resin core 1 is
By maintaining its shape, the desired molded product 6
In addition to contributing to the formation of the above, and after the molding, the molded product 6 is melted and removed by the residual heat, so that the residual component can be removed without leaving.

Therefore, it is possible to prevent defects such as abrasion and breakage of the product, improve the quality of the molded product, improve the yield, and further save time and cost. It becomes possible to improve the sex.

Further, as well shown in FIG.
By removing the molded product 6 formed as described above from the molding die 4 and removing the resin core 1 as described above, the molding is completed. Therefore, unnecessary parts such as burrs of the molded product 6 are removed. A molded product 6 which is a desired finished product is formed.

The molded product 6 thus formed is a molded product in which the occurrence of defects is prevented and which is excellent in appearance quality and functional quality.

The special molding core of the present invention is applied to various molding methods such as injection molding adopted as a part of plastic molding and injection molding adopted as a 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.

Therefore, as compared with the case where a molded product is obtained by casting using a metal core which is widely used as a conventional core, the size and shape of the molded product are not restricted, and It is possible to mold a shape and size, significantly reduce man-hours, and efficiently obtain a molded product with excellent quality.

As described above, according to the molding core of the present invention, the shape of the molding core is maintained at the time of molding to contribute to the formation of a desired molded article, and after molding, the molding is performed. The product is melted and removed by the residual heat of the product, leaving no residue, and the special molding core 1 can be easily removed from the molded product 6, and the range of material selection can be significantly expanded. In addition to being easy and cost-saving, it is possible to prevent defects such as wear and breakage of products, improve the quality of molded products, improve yield, and save time and money. Therefore, the productivity can be improved.

Also, as one of the embodiments of the present invention, when the special molding core is applied to a plastic molding or a ceramic molding which is a molding method other than the casting method, it is limited to the injection molding of the above embodiment. Needless to say, the present invention can be applied to other molding methods without being affected, and many modifications can be considered, and the same effects as those of the above-described embodiments can be obtained.

The resin core 1 of the present embodiment has pressure resistance (non-disintegration) at the time of molding the molded product 6 and, after molding, heat which is removed and lost by residual heat of the molded product. Although it is required to have a disappearance property (removability), synthetic resin (plastic) and other materials can be cited as core materials satisfying this condition. Of these, synthetic resin (plastic) is There are 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 the thermoplastic synthetic resins are fluororesins (polyfluoroethylene resins) such as tetrafluoroethylene resin, polyimide resins, polyamide-imide resins and polysulfone resins, and any 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 meet 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,
Not only the above-mentioned synthetic resin (plastic) but also a pressure-resistant (non-disintegrating) property at the time of molding for molding the molded product 6, and a heat-dissipating property which is removed and disappeared by residual heat of the molded product after molding ( Of course, synthetic resin (plastic) other than the above examples can also be used as long as it has the same removability) and does not give a bad influence to the cast product such as generating a large amount of gas during casting. It is possible to obtain the same effect as that of the above embodiment.

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) By using a special core, conditions such as pressure resistance and heat resistance required for the core can be relaxed, and the selection range of the core material can be expanded. (2) By using a special core, the pressure resistance and heat resistance of the core can be adjusted by selecting the material and the amount thereof. (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-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. 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.

Further, even when a molded article 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, it is possible to efficiently obtain a desired molded product having excellent quality.

The productivity can be improved and the range of application can be increased. By using the special molding core, molding of the core is facilitated, molding equipment is simplified, and the number of steps is 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 advantages such as reduction of time and cost.

Next, FIG. 5 shows a third embodiment of the molding special core of the present invention. The resin core 1 as the non-sand core which is the molding special core has its surface (outer surface). The protective layer 7 is formed on.

The protective layer 7 meets the conditions of heat resistance during molding and thermal burnout after molding.

The protective layer 7 is, for example, a heat resistant protective layer made of a heat resistant resin or the like.

As the material for forming the heat-resistant protective layer 7, heat-resistant rubber such as silicon rubber and fluororubber, heat-resistant synthetic resin (plastic) resin such as silicon resin and fluororesin, low melting point metal, new material There are ceramics (fine ceramics) and other heat resistant materials.

According to such a molding core 1, it is possible to further improve the pressure resistance (non-disintegrating property) during molding without impairing the heat dissipation property (removability) after molding. Since it is provided with a condition that does not adversely affect the molded product such as generation of a large amount of gas during molding, it is possible to contribute to efficiently obtain a molded product having excellent quality.

Then, using the resin core 1 having the protective layer 7 formed on the surface (outer surface) thereof, a cast product, a plastic molded product, a ceramic molded product, etc. can be produced in the same manner as in the above-mentioned embodiment. The molded article of can be formed.

In this case, the resin core 1 having the protective layer 7 formed on the surface (outer surface) is arranged between the upper mold 2 and the lower mold 3 to form the molding die 4 having the cavity 5. After that, in the same manner as in the above-described embodiment, the target molding 6 can be molded by injecting the molding material into the cavity 5 formed inside the molding die 4.

Next, FIG. 6 shows a fourth embodiment of the molding special core of the present invention, and a molding special core made of rubber (hereinafter referred to as "rubber core") will be described.

That is, the rubber core 1 which is the special molding core is made of a heat-resistant synthetic rubber, silicon rubber, fluorine rubber or the like, and is hollow as shown in FIG. It is formed in a hollow shape having a portion S.

Even in this case, the rubber core 1 has pressure resistance (non-disintegration property) at the time of molding the molded product, and after the molding, is removed by the residual heat of the molded product and disappears. Since it has heat-dissipating property (removability) and conditions that do not adversely affect the molded product such as generation of a large amount of gas during molding, it is possible to efficiently obtain a molded product with excellent quality. Can contribute to that.

By using the rubber core 1 which is the molding special core, a molded product such as a cast product, a plastic molded product or a ceramic molded product can be formed.

For example, the rubber core 1 is disposed between the upper mold 2 and the lower mold 3 to form the molding die 4 having the cavity 5, and then the molding is carried out in the same manner as in the above embodiment. By injecting the molding material into the cavity 5 formed inside the molding die 4, the desired molded product 6 can be molded.

In this case, the temperature of the molding material is considerably lower than the initial temperature by the time it reaches the cavity 5 of the molding die 4, so that the rubber core 1 has improved pressure resistance. Together with this, the temperature rise of the rubber core 1 during injection of the molding material is relatively small due to its own temperature and heat capacity, the heat resistance to the molding material is high, and the pressure resistance is also improved. Even when the high-pressure molding material is injected, the initial shape can be maintained without thermal deformation or pressure deformation such as immediate melting due to the reflection effect and the temperature effect.

The special core for molding of 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 to improve the quality of molded products. However, the present invention is not limited to the above-described embodiment, and many modifications can be considered.

For example, the special core of the above embodiment has a hollow shape from the viewpoints of weight reduction, cost reduction, and ease of disintegration / removal after molding, but is not limited to this. Needless to say, a solid shape can be used in view of non-disintegration at the time of molding.

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.

Further, the material for 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, and the pressure resistance (non-disintegration) at the time of molding the molded product is obtained.
In addition to the above, a core that has heat dissipation properties (removability) that is removed and lost by residual heat of the molded product after molding, may be used, including low melting metals such as tin, lead, and antimony, ceramics, and other simple metals. FR can be used as one material
R (fiber reinforced rubber) and FRP (fiber reinforced plastic)
Alternatively, GFRP (glass fiber reinforced plastic) or other composite material can be used, and a special molding core using various materials is conceivable, and the same effects as those of the above-described embodiments can be obtained.

Next, FIG. 7 shows a fifth embodiment of the molding special core of the present invention. The resin core 1 as the non-sand core which is the molding special core has its surface (outer surface). The coating layer 8 is formed on.

The molding special core 1 of this embodiment is
Core body H made of synthetic resin (plastic)
And a heat-resistant synthetic resin of a certain thickness integrally formed on the surface of the core body so as to protect the core body by maintaining the original shape without melting even in the molten metal during casting or residual heat after casting And a coating layer 8.

Further, the core main body H has a trade-off condition between the pressure resistance (non-disintegration) during casting and the disintegration after casting, and is suitable for molded articles which generate a large amount of gas during molding. It is required to satisfy the condition that no adverse effect is given.

Further, the coating layer 8 protects the core body by holding the original shape without melting due to high heat during molding and residual heat after molding, and is a heat resistant coating made of, for example, a heat resistant resin. There are layers.

Further, as a material for forming the heat resistant coating layer 8, there is silicon having excellent heat resistance such as silicon resin or silicon rubber, and the original shape thereof is not melted by high heat during molding and residual heat after molding. It can be held to protect the core body H.

According to such a molding special core 1, the pressure resistance (non-disintegration) during molding is further improved without impairing the heat dissipation property (removability) of the core body H after molding. In addition, it is possible to further improve the conditions that do not adversely affect the molded product such as generating a large amount of gas at the time of molding, so that a perfect molded product can be efficiently obtained. You will be able to contribute to that.

Then, using the resin core 1 having the coating layer 8 formed on the surface (outer surface) thereof, a cast product, a plastic molded product, a ceramic molded product, etc. are produced in the same manner as in the above-mentioned embodiment. The molded article of can be formed.

In this case, the resin core 1 as a molding special core having the coating layer 8 formed on the surface (outer surface) is used as the upper mold 2.
And a lower mold 3 and a molding mold 4 having a cavity 5
After forming the above, the target molded product 6 can be molded by injecting the molding material into the cavity 5 formed inside the molding die 4 in the same manner as in the above-described embodiment. .

The core body H is melted and removed by the residual heat of the molded product 6 after a predetermined time has elapsed after the molding material was injected into the cavity 5 and molded.

However, the heat-resistant coating layer 8 is very excellent in heat resistance and retains its original shape without being melted by the residual heat of the molded product not only during molding but also after molding. The core body H is wrapped in a sealed state to protect it, and the core body H is melted and removed by the residual heat of the molded product 6, so that the core body H contains an organic synthetic resin. Even if the gas is generated, it is possible to completely prevent the special core 1 for molding from generating gas, and it is possible to prevent the components of the core body H from penetrating into the molded product 6. It is possible to prevent adverse effects, prevent defects in the molded product 6, prevent defective products from being formed in the molded product 6, and contribute to formation of the desired molded product 6.

In the heat resistant coating layer 8, since the inner core body H is melted and removed by the residual heat of the molded product 6,
Since the inside of the molded product 6 has an empty bag shape (balloon state), it can be easily taken out.

In this embodiment, there are the following effects.

(1) The heat-resistant coating layer that protects the core body so as to wrap it inside prevents the components of the core body from penetrating into the molded product, thereby preventing adverse effects on the molded product. However, it is possible to prevent the occurrence of defects in the molded product and prevent the generation of defective molded products, thereby improving the yield and improving the productivity. (2) Since the heat-resistant coating layer of a predetermined thickness made of a synthetic resin such as silicon having excellent heat resistance is integrally formed on the surface of the core body, the core body can be protected so as to be wrapped inside. The shape retention function of the special molding core during injection of the molding material is improved, and the initial shape can be retained more reliably without melting in the molding material, resulting in superior dimensional accuracy and better quality of the molded product. It can be done. (3) In particular, since synthetic resins such as silicon are excellent in flexibility and elasticity, they can form a uniform wall thickness from thin to thick ones, and from small to large ones regardless of size. A heat-resistant coating layer can be formed on the surface of the child body with a predetermined thickness, and even complicated shapes can be easily integrally formed, the molding work is simplified, and the finished product can be easily obtained.
Furthermore, the quality of the molded product can be further improved. (4) In particular, since silicon has excellent heat resistance and releasability, it does not adhere to the molded product, and it retains its original shape without being melted by the residual heat after casting as well as during molding. Since the core body is protected by this, molding is easy and the core can be easily removed after molding, and a finished product with excellent quality can be easily obtained. (5) Especially, since the main element of silicon is inorganic silicon (Si), no gas is generated at the time of molding, and even if the core body contains an organic synthetic resin, it is not necessary at the time of molding. It retains its original shape without melting even with residual heat after molding, and protects the core body, which is melted and removed by residual heat of the molded product, by enclosing it in a sealed state to protect gas generation from the special molding core. Also, it is possible to prevent adverse effects on molded products and improve the quality of finished products. (6) In particular, since silicon is excellent in flexibility, elasticity, and releasability, and has high strength, it can be used as a non-disintegrating core not only for direct punching but also for deformation punching. It is easy to pull out the special core for use, and it is easy to mold the molded product.

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

[0125]

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) By using a special core, there are advantages that the conditions such as pressure resistance and heat resistance required for the core can be relaxed and the selection range of the core material can be expanded. (2) The use of a special core has the advantage that the pressure resistance and heat resistance of the core can be adjusted by selecting the material and the amount thereof. (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 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, in the molding special core of the present invention, a coating layer is formed on the surface (outer surface) for protecting the core body while maintaining the original shape without melting to the high heat during molding and the residual heat after molding. In such a case, there are the following excellent effects.

(9) The coating layer for protecting the core body so as to wrap it inside prevents the components of the core body from penetrating into the molded article, thereby preventing adverse effects on the molded article. There are advantages that it is possible to prevent the occurrence of defects in the molded product, prevent the defective product from being generated, and improve yield and productivity. (10) In particular, since a coating layer of a predetermined thickness made of synthetic resin such as silicon having excellent heat resistance is integrally formed on the surface of the core body, it is possible to protect the core body so as to wrap it inside. The shape retention function of the special core for molding is improved,
By holding the initial shape more reliably without melting during molding, there is an advantage that the dimensional accuracy is excellent and the quality of the molded product can be further improved. (11) Since synthetic resin such as silicon is particularly excellent in flexibility and elasticity, it is possible to form a uniform thickness from a thin one to a thick one, and a medium size from a small one to a large one. A coating layer can be formed on the surface of the child body with a predetermined thickness, and even complicated shapes can be easily formed integrally, molding work is easy, and finished products can be obtained easily, and the quality of molded products is even better. There is an advantage that can be done. (12) In particular, silicon has excellent heat resistance and releasability, so it does not adhere to the molded product, and it does not melt not only in the molten metal during molding but also in the residual heat after molding. Since the core body is protected by holding the core, the molding is easy, and the core can be easily removed after molding, so that a finished product having excellent quality can be easily obtained. (13) In particular, the main element of silicon is inorganic silicon (Si).
As a result, no gas is generated during molding, and even if the core body contains an organic synthetic resin, it retains its original shape without being melted by the residual heat after molding as well as during molding. Since the core body that is melted and removed by the residual heat of the core is wrapped in a sealed state to protect it, gas generation from the core can be completely blocked, adversely affecting the molded product can be prevented, and the quality of the finished product can be improved. There are advantages. (14) Especially, since silicon is excellent in flexibility, elasticity, and releasability, and has high strength, it can be used as a non-disintegrating core not only for direct punching but also for deformation punching. It is easy to pull out the special core for use, and there is an advantage that molding of the molded product can be facilitated.

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 special molding material 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 is facilitated, molding equipment is simplified, and the number of steps is 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 sectional view showing a third embodiment of the special molding core.

FIG. 6 is a sectional view showing a fourth embodiment of the molding special core.

FIG. 7 is a sectional view showing a fifth 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) 7 Protective layer (Heat resistant protective layer) 8 Coating layer (Heat resistant coating layer) H Core body S Hollow part

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, or a ceramic molded product. A special molding core, which is formed from a sand core. 2. The special core for molding according to claim 1, wherein a core having a reciprocal condition of pressure resistance during molding and disintegration after molding is used as the non-sand core. . 3. A special molding core according to claim 1 or 2, wherein a core 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 made of rubber is used as the non-sand core. 5. As the non-sand core, a core having a protective layer formed on the surface of the core body, which has a trade-off between heat resistance during molding and thermal burnout after molding, is used. The special molding core according to any one of claims 1 to 4, which is characterized in that. 6. A non-sand core comprising a core body, on the surface of which a coating layer is formed to protect the core body by maintaining its original shape without melting due to high heat during molding and residual heat after molding. The special core for molding according to any one of claims 1 to 4, which is used. 7. The special molding core according to claim 6, wherein the coating layer is made of silicon.