JP3248012B2 - Cast products cast using a special core - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cast product using a special core, and more particularly, to a cast product using a special core other than a sand core, which has been generally used as a core. Thus, the present invention relates to a cast product using a special core that can be efficiently formed without being restricted by the shape, even if the shape is a complicated shape such as a hollow shape or an undercut shape.

[0002]

2. Description of the Related Art In casting employed as a part of machine work, a non-collapsible core or a collapsible core is used to form a hollow portion or an undercut portion. I was getting it. By the way, as the former (non-collapseable core),
Although there is a metal core, it cannot be used except that it can be directly punched or deformed, and its use range has been limited to that of a specific shape.

As the latter (collapseable core), a sand core is generally used, but molding is difficult and
There is a problem that not only is it easy to disintegrate and it is difficult to handle, but also it is difficult to satisfy the reciprocal condition between the pressure resistance during casting and the disintegration after casting.

Therefore, in recent years, it has been proposed to obtain a cast product by casting using a core obtained by applying a special coating to the surface of the sand core, but there are the following problems.
The problem was not solved. (1) Coating is difficult, for example, it is necessary to form not only one layer but also a plurality of layers. Therefore, the coating is time-consuming and time-consuming, not only takes time and expense, but also takes time and cost. The initial purpose is also difficult to achieve. (2) Since it is difficult to completely remove the binder as a component of the coating layer and the sand core after casting, sand baking treatment for removing the coating layer and the binder is required. It takes time and money. (3) Since sand cores are difficult to mold, not only equipment and man-hours are required, but the molded sand cores are also fragile, difficult to handle, require man-hours, and have a low yield.
It takes time and money. (4) Since the sand core requires pressure adjustment to prevent collapse during casting, and it is difficult to completely collapse after casting, a heat treatment step, a dropout step, and a dropout inspection are required. It takes man-hours, time and money. (5) Defective products are liable to occur, such as intrusion of molten metal between core sand particles during casting, and formation of cavities in the cast product due to penetration of components of the sand core into the cast product. The yield of casting is poor, and the productivity is poor. (6) It is difficult to completely remove the core sand after casting, and it adheres to a cast product, and causes problems such as wear and breakage of the product. (7) Casting of a complicated shape or a large casting is difficult or practically impossible, so that its application range is limited. (8) When the sand of the sand core is reused after casting, since the coating layer and the binder are contained, it is difficult to completely remove the coating layer and the binder. And
It takes time and money. (9) Sand cores have drawbacks such as difficulty in molding, easily disintegrating, and difficult handling, and it is difficult to satisfy reciprocal conditions of pressure resistance during casting and disintegration after casting. It requires many steps and the yield is low, and it takes time and money.

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

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems by adopting the following constitution. That is, (1) By using a special core that is hard to break as a core,
The molding and handling of the core is easy, reducing man-hours, reducing time and costs, and obtaining high quality cast products. (2) By using a special core that does not use a penetrating component such as a binder, the core component is prevented from penetrating into a casting, and the occurrence of defects such as the formation of a cavity is prevented. In addition, it is possible to prevent the occurrence of defective cast products, thereby contributing to improvement in yield and productivity, and to obtain cast products with excellent quality. (3) By using a special core which has the reciprocal conditions of pressure resistance during casting and disintegration after casting, it is possible to avoid the occurrence of insertion of molten metal during casting and to avoid pressure adjustment to prevent pressure (non-collapse). ) And complete disintegration (disintegration) of the core after casting and easy removal of the core component, preventing adhesion to the casting, and casting such as wear and breakage of the casting. Prevent the occurrence of product defects and obtain cast products of excellent quality. (4) The use of a special core facilitates the formation of hollow sections and undercut sections, and furthermore, by improving the core strength,
It enables casting of all shapes and sizes without being restricted by the shape and size, thereby expanding the applicable range and obtaining cast products with excellent quality. (5) Special cores do not contain hard-to-remove components such as binders, making it easy to completely disintegrate and remove cores after casting, making it easy to reuse, preventing pollution and reducing man-hours. Reduce, save time and money and get better quality castings.

[0007]

According to the present invention, there is provided a method for forming a mold by using a non-sand core as a core, and forming the mold by using the mold. This is achieved by providing a cast product using a special core characterized by the following.

[0008]

According to the present invention, the following effects are obtained.

That is, according to the present invention, a mold is formed using a special core as a core, and casting is performed using the mold, thereby obtaining a cast product. The idea is to obtain high quality cast products efficiently by expanding the range. (1) By using a hard-to-break special core as the core,
The molding of the core is facilitated, the molding equipment is simplified, the number of steps is reduced, the time and cost are reduced, and a high quality cast product is efficiently obtained. (2) Use of a hard-to-break special core as the core makes it easy to handle because it does not break when dropped or thrown, making it easy to transport and store, and eliminates the need for pressure adjustment during casting. Is reduced, time and cost are reduced, and a cast product having excellent quality is efficiently obtained. (3) Since the special core used does not contain a penetrating component such as a binder, penetration of a core component into a cast product is prevented, so that occurrence of a defect such as a cavity is prevented, and casting is performed. The occurrence of defective products is prevented, and the yield and the productivity are improved, so that a cast product having excellent quality can be efficiently obtained. (4) By using a special core as the core, it becomes easy to form a hollow portion or an undercut portion, and the core strength is improved. Casting becomes possible, the scope of application is expanded, and cast products with excellent quality are obtained efficiently. (5) By using a special core that has the reciprocal conditions of pressure resistance during casting and disintegration after casting,
It avoids the occurrence of molten metal insertion during casting, avoids pressure adjustment, maintains pressure resistance (non-collapsed), and completely removes core (collapse) and core components after casting. The present invention makes it easy to prevent adhesion to a casting, prevents occurrence of a failure of the casting such as abrasion and breakage of the casting, and efficiently obtains a casting of excellent quality. (6) Special cores used as cores do not contain components that are difficult to remove, such as binders, so that complete disintegration and removal of the cores are easy, and reuse is easy, and pollution is generated. In addition, the number of steps can be reduced, time and cost can be reduced, and a cast product excellent in quality can be efficiently obtained.

[0010]

BRIEF DESCRIPTION OF THE DRAWINGS The invention will now be described in more detail with reference to the accompanying drawings, in which: FIG.

FIGS. 1 to 4 show an embodiment of a cast product cast using the special core of the present invention.

That is, the present invention does not use a sand core which is generally widely used as a core, but uses a non-sand core made of a material other than the sand core which is usually considered difficult or unusable. A cast product formed using a special core, which is formed by forming a mold using a core, and casting using the mold.

The non-sand core used in the present invention comprises:
It is required to satisfy both conditions of pressure resistance (non-collapse property) at the time of casting and complete collapse (collapse property) after casting.

Further, the non-sand core is required to satisfy conditions that do not adversely affect the casting, such as generating a large amount of gas during casting.

In this embodiment, a case where a casting is cast using a core made of a synthetic resin (plastic) as the non-sand core will be described.

That is, in the case of casting a casting using a non-sand core made of the synthetic resin (plastic), as one embodiment, a case of obtaining a casting by die casting will be described. .

The synthetic resin core (plastic core) 1 (hereinafter referred to as “resin core”), which is a core made of a synthetic resin (plastic) as the non-sand core, is formed of a synthetic resin (plastic). I have. The resin core 1 is made of a synthetic resin (plastic) by a synthetic resin molding method (plastic molding method) such as injection molding.
It is molded into a resin core 1 having a hollow portion S as well shown in FIG. The resin core 1 is shown in FIG.
The mold 4 is formed by disposing between the upper mold 2 and the lower mold 3 as shown in FIG.

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

As shown in FIGS. 2 and 3, a molten metal such as an aluminum molten metal is poured into the cavity 5 formed in the mold according to the material of the casting. Then, a casting 6 having a shape corresponding to the shape of the cavity 5 is formed.

Further, as best shown in FIG.
Since the casting is completed by removing the casting 6 formed as described above from the mold 4, unnecessary portions such as burrs of the casting 6 are removed, and the casting 6 as an intended finished product is removed. Is formed.

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

Therefore, by casting using a sand core, which is generally widely used as a conventional core, the number of steps is greatly reduced as compared with the case where a cast product is obtained, and a cast product having excellent quality is obtained. It can be obtained efficiently.

The resin core 1 retains its shape at the time of casting, thereby contributing to the formation of the desired cast product 6 and, after casting, is melted by the residual heat of the cast product 6. And no residue remains.

In this case, the temperature of the molten metal is considerably lower than the initial temperature (for example, about 660 ° C. in the case of an aluminum melt) before reaching the cavity 5 of the mold 4.

The resin core 1 retains its initial shape without being immediately melted by the reflection and temperature effects even if the molten metal acts due to the temperature and latent heat of the resin core itself. The resin core 1 is melted and removed by the residual heat of the casting 6 after a predetermined time has elapsed after the molten metal has been poured into the hollow portion 5 and the molten metal has cooled and solidified.

FIG. 5 shows a second embodiment of the special core used in the present invention. The resin core 1 as a non-sand core, which is a special core, has its surface (outer surface). Is coated with a protective layer 7.

The protective layer is a heat-resistant coating layer made of a heat-resistant resin or the like.

Examples of the material for forming the heat-resistant coating layer include heat-resistant resins such as silicon rubber and silicone resin, low-melting metals, new ceramics (fine ceramics), and other heat-resistant materials.

Incidentally, the special core used in the present invention is not limited to the above-described embodiment, but can be applied to various shapes using various special cores to improve the quality of a cast product. The present invention is not limited to the above embodiment, and many modifications can be made.

For example, the special core of the above embodiment has a hollow shape in terms of weight reduction, cost reduction, and ease of collapse and removal after casting, but is not limited thereto. Of course, it can be made into a solid shape from the viewpoint of non-disintegration at the time of casting.

Incidentally, the cast product cast using the special core of the present invention is not limited to the one formed by the casting method of the above-described embodiment, but a specific process is added to further improve the quality of the cast product. Thus, the present invention is not limited to the cast product using the special core of the above-described embodiment, and many modified examples are conceivable.

Further, the core made of synthetic resin (plastic) as the non-sand core, which is the special core of the present embodiment, has the reciprocal conditions of pressure resistance during casting and disintegration after casting, and It is required that the material does not adversely affect the cast product, such as generating a large amount of gas at the time of casting, and the following synthetic resin (plastic) as a core material satisfying this condition is required. is there.

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

The most suitable thermoplastic synthetic resin is a fluororesin (polyfluoroethylene resin) such as an ethylene tetrafluoride resin, a polyimide resin, a polyamideimide resin, or a polysulfone resin. And a cast product satisfying the initial purpose can be obtained.

Further, next to this, there are polyamide resin (nylon resin) and polypropylene resin, which satisfy both of the above conditions, and can provide a cast product satisfying the initial purpose.

Other examples include a polyethylene resin, a polyester resin (tetron resin) and a polysulfone sun resin, which satisfy both of the above conditions and provide a cast product satisfying the initial purpose. be able to.

The core made of a synthetic resin (plastic) used for the special core for casting of the present embodiment is not limited to the above-mentioned synthetic resin (plastic). As long as it has the reciprocal condition of collapsibility and does not give a bad effect on the cast product such as generating a large amount of gas at the time of casting,
It is a matter of course that a thermosetting resin such as a silicone resin and other synthetic resins (plastics) other than the above embodiment can be used, and the same effects as those of the above embodiment can be obtained. Further, the non-sand core as a special core used in the casting of the present invention is not limited to the resin core made of the synthetic resin (plastic) of the above embodiment, but may be made of any other material than the synthetic resin (plastic). Needless to say, a non-sand core made of a material can be used, and the following non-sand cores as special cores other than synthetic resin (plastic) are available.

That is, for example, there are low melting point metals, new ceramics (fine ceramics) and other materials.
A non-sand core is formed using these materials, a mold is formed using the non-sand core, and a casting can be manufactured using the mold. be able to.

In the above embodiment, as one of the cases in which a casting is obtained by using a core made of a synthetic resin (plastic) as a non-sand core as a special core to obtain a cast product, casting is performed by die casting. I explained how to get the product,
Cast products cast using the special core of the present invention are not limited to the die casting, but can be used in sand casting gravity casting, die gravity casting, low pressure casting, precision casting, and other casting methods. By applying the same, it is needless to say that a desired cast product can be obtained, and the same effect as in the above embodiment can be obtained.

It should be noted that the cast product cast using the special core of the present invention is not limited to the cast product cast using the special core of the above embodiment, and many variations are conceivable.

Next, the operation of the cast product using the special core according to the present embodiment will be described.

As described above, according to the present invention, a mold is formed by using a non-sand core as a core, and casting is performed using the mold, thereby obtaining a cast product. The idea is to obtain a cast product with excellent quality efficiently by improving the properties and expanding the applicable range, and has the following effects. (1) By using a non-sand core that is hard to break as a core,
The molding of the core is facilitated, the molding equipment is simplified, the number of steps is reduced, time and cost are reduced, and a cast product having excellent quality can be efficiently obtained. (2) Since a non-sand core, which is hard to break, is used as the core, it will not break even if dropped or thrown, making it easy to handle, making transport and storage easy, and eliminating pressure adjustment during casting. Man-hours are reduced, time and cost are reduced, and a cast product having excellent quality can be efficiently obtained. (3) Since a penetrating component such as a binder is not used, a core component is prevented from penetrating into a cast product, thereby preventing the occurrence of a defect such as a cavity and the like, thereby preventing a defective product from occurring in a cast product. By improving the yield and the productivity, it is possible to efficiently obtain cast products having excellent quality. (4) By using a non-sand core, it is easy to form a hollow portion or an undercut portion, and the core strength is improved. Casting becomes possible, and the range of application can be expanded, so that a cast product excellent in quality can be efficiently obtained. (5) By using a special core that has the reciprocal conditions of pressure resistance during casting and disintegration after casting,
It avoids the occurrence of molten metal insertion during casting, avoids pressure adjustment, maintains pressure resistance (non-collapsed), and completely removes core (collapse) and core components after casting. This makes it easy to prevent adhesion to the casting, prevents the occurrence of casting defects such as abrasion and breakage of the casting, and efficiently obtains a casting of excellent quality. (6) Since non-sand cores do not contain components that are difficult to remove, such as binders, complete disintegration and removal of the cores are easy, and reuse is easy and easy, preventing pollution. In addition, the number of processes can be reduced, and time and cost can be reduced, so that a cast product having excellent quality can be efficiently obtained.

It should be noted that the cast product cast using the special core of the present invention is not limited to the above-described embodiments, and many variations are conceivable.

[0044]

As described above, according to the present invention, a mold is formed by using a non-sand core as a core, and a cast product is obtained by using the mold, thereby improving the productivity and expanding the applicable range. By
The idea is to efficiently obtain a cast product having excellent quality, and has the following excellent effects. (1) By using a non-sand core that is hard to break as a core,
There are advantages that the molding of the core is easy, the molding equipment is simplified, the number of steps is reduced, time and cost are reduced, and a cast product having excellent quality can be efficiently obtained. (2) Since the core is made of a non-sand core that is hard to break, it will not break even if dropped or thrown, making it easy to handle, making it easy to transport and store, and eliminating the need for pressure adjustment during casting. There is an advantage that the number of steps can be reduced, time and cost can be reduced, and a cast product excellent in quality can be efficiently obtained. (3) Since a penetrating component such as a binder is not used, a core component is prevented from penetrating into a cast product, thereby preventing the occurrence of a defect such as a cavity and the like, thereby preventing a defective product from occurring in a cast product. In addition, there is an advantage that the yield can be improved and the productivity can be improved, so that a cast product having excellent quality can be efficiently obtained. (4) By using a non-sand core, it is easy to form a hollow portion or an undercut portion, and the core strength is improved. Casting is possible, and there is an advantage that a cast product having excellent quality can be efficiently obtained by expanding the applicable range. (5) By using a special core that has the reciprocal conditions of pressure resistance during casting and disintegration after casting,
It avoids the occurrence of molten metal insertion during casting, avoids pressure adjustment, maintains pressure resistance (non-collapsed), and completely removes core (collapse) and core components after casting. There is an advantage that casting can be easily performed, adhesion to castings can be prevented, casting defects such as abrasion and breakage of castings can be prevented, and high quality castings can be efficiently obtained. (6) Since non-sand cores do not contain components that are difficult to remove, such as binders, complete disintegration and removal of the cores are easy, and reuse is easy and easy, preventing pollution. In addition to this, there is an advantage that the number of steps can be reduced, time and cost can be reduced, and a cast product excellent in quality can be efficiently obtained.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a case where a mold is formed using a resin core that is a non-sand core among cast products cast using a special core of one embodiment according to the present invention.

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

FIG. 3 is a cross-sectional view showing a cast product obtained by taking out from a mold, among cast products cast using a special core according to one embodiment of the present invention.

FIG. 4 is a cross-sectional view showing a resin core which is a non-sand core used for molding a cast product using the special core of one embodiment according to the present invention.

FIG. 5 is a sectional view showing a second embodiment of the resin core.

[Explanation of symbols]

1 resin core (synthetic resin core: plastic core)
(Non-sand core which is a special core) 2 Upper die 3 Lower die 4 Mold 5 Hollow part 6 Cast product 7 Protective layer S Hollow part

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) B22C 9/10 B22C 1/00 B22D 17/22 B22D 25/02

Claims (3)

(57) [Claims] The present invention does not use casting sand or plaster at all as a core. <br/> A hollow or undercut shape is used by using a non-sand core.
By covering the entire inner wall of the cave (the inner wall of the casting)
A cast product formed using a special core, formed by forming a mold having a hollow portion formed therein while protecting an inner wall surface thereof , and casting the mold using the mold. 2. A non-sand core, which prevents deformation and alteration during casting to protect the inner wall surface of the cast product.
Using a core having a both conditions of the disintegrating be lost by heat melting or the like after the casting and pressure resistance (non-disintegrating) during casting to form Te, high heat and high pressure of the molten metal during casting
Castings and the high thermal and high pressure of the molten metal is cast using a special core according to claim 1, characterized in that it is formed by the <br/> casting die casting or the like acting I. 3. A non-sand core, which does not deform even when high heat and high pressure of molten metal at the time of casting act.
3. A casting made by using a special core according to claim 1 or 2, wherein the core is formed by casting using a core made of a synthetic resin (plastic) having flexibility. Goods.