JP2563750Y2 - Volume increasing material for mold making - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a volume increasing material for mold making, which is filled in place of casting sand behind a sand layer in various molds.

[0002]

2. Description of the Related Art Conventionally, in various molds used for casting molten metal, in order to reduce the casting cost, to reduce the amount of molding sand used, that is, to reduce the sand / metal (S / M) ratio. It is known that an appropriate volume increasing material is embedded in an intermediate portion of a casting sand forming a mold except for a skin sand layer in contact with a molten metal. In particular, the use of this volume increasing material is considered as one effective means for reducing the cost of an organic self-hardening mold using expensive organic self-hardening molding sand. As such a volume-increasing material, it is desirable to have magnetism from the viewpoint of workability of separation from casting sand after completion of casting, etc., and high heat resistance, impact resistance, etc.
It is required to be inexpensive.

In order to satisfy these requirements, Japanese Patent Application Laid-Open No. 220220/1990 discloses a structure in which a powdery or small lump-shaped magnetic material is distributed over the entire ceramic ball, or a magnetic material disposed in the center. A ceramic ball having a structure in which a ceramic layer is provided outside the spherical core body has been proposed as a volume increasing material, and further fired in a state where the ceramic layer is formed into a divided shape. Then, it is also considered that a ceramic ball having a magnetic core at the center is configured by housing a spherical magnetic core at the center of the divided fired bodies and bonding them with an appropriate adhesive or the like. I have.

[0004] However, in the above-described configuration in which the ceramic ball itself is made of a magnetic material, there is a problem that the manufacturing cost is increased and the specific gravity is increased. In any case, since the ceramic layer exists outside the substantially spherical magnetic core so as to be substantially spherical at a predetermined thickness, when the diameter increases,
At the time of unraveling after the end of the casting operation, when it is recovered by a predetermined magnetic separation device, its magnetic adhesion cannot be sufficiently performed,
Therefore, it is necessary to increase the magnetic force of the separation device, and the size of the ball is limited, so that the number of balls used inevitably increases, thereby increasing the casting cost. The problem was inherent.

[0005]

Here, the present invention has been made in view of such circumstances, and the problem to be solved is that the magnetic adhesion can be extremely effectively performed, so that separation and It is not necessary to increase the magnetic force for recovery, and the size of the volume-increasing material itself can be appropriately selected according to the mold, and the cost of the volume-increasing material itself, and therefore, the mold using such a volume-increasing material It is an object of the present invention to provide a mold increasing volume increasing material which can advantageously reduce the cost of the mold.

[0006]

According to the present invention, in order to solve the above-mentioned problems, a casting sand is filled in place of a sand layer in a mold instead of a sand layer, and magnetically separated from the casting sand after casting. In the volume increasing material, a solid or hollow longitudinal rod-shaped core made of a magnetic material is inserted into a through-hole provided in an integral ceramic body of a predetermined size .
To the opening end of the through hole.
Then, the end of the rod-shaped core body is mechanically engaged,
Prevents rod-shaped core from being pulled out of the ceramic body
By being configured to, in which as its gist.

[0007]

[0008]

According to the structure of the present invention, the core made of a magnetic material has a long rod shape, unlike the conventional spherical shape, and is arranged in the through hole of the ceramic body. Thus, a predetermined length is secured in the direction of the line of magnetic force, so that the magnetic adhesion to the longitudinal end of the core body can be advantageously increased.

[0009] Moreover, in the present invention, the rod-shaped core is provided so as to penetrate through the ceramic body, and by mechanical engagement, from where according rod-like core member is caused to expose at its end, its Strong magnetic adhesion is exerted on the exposed end, thereby enabling effective magnetic separation.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, in order to clarify the present invention more specifically, some embodiments of the present invention will be described in detail with reference to the drawings. First, FIG. 1 shows an example of a volume increasing material effective for understanding the present invention.
Has a spherical shape as a whole, and alumina,
Cordierite, mullite, silicon carbide, silicon nitride,
A spherical ceramic body 4 made of a predetermined ceramic material such as zirconia;
And a long rod-shaped core 6 made of a predetermined magnetic material such as mild steel and arranged in the diametrical direction.

In the volume increasing material 2 having such a structure, since the magnetic adhesion to both end portions (the left and right portions of the spherical shape in the figure) of the rod-shaped core body 6 becomes strong, after the casting is completed, the magnetic separation device or the like is used. When the volume increasing material 2 is separated from the mold (casting sand) by a predetermined separation / recovery means, the magnetic force of the magnetic separation device effectively acts,
That is, the magnetic adhesion of the volume increasing material is advantageously performed, so that separation and recovery can be performed effectively.
However, the volume increasing material according to the present invention is such a rod-shaped core body.
By devising the structure of
It is showing signs .

Namely, good Masui an example of the volume-increasing agent according to the present invention have been shown in FIGS. 2 and 3,
Their Of these, the volume increase member 8 shown in Figure 2,
A main body 10 made of a predetermined ceramic material and having a substantially elliptical spherical shape or a thick cylindrical shape is provided with a pin 1 having a predetermined length as a rod-shaped core in a through hole 12 penetrating the center thereof.
4 has a structure in which the pin 1 is inserted.
4 is brought into contact with one opening of the through hole 12, and a caulking portion 18, which is the other end of the pin 14, is brought into contact with the other opening of the through hole 12. By being caulked and fixed, the pin 14 is attached to the main body 10.
Is attached so as not to get out of the through-hole 12 and has an integrated structure.

The volume increasing material 2 shown in FIG.
0 is the through hole 24 of the ceramic body 22 in the same manner.
, A bolt 28 is inserted, one end 32 of the bolt 28 is locked in one opening of the through hole 24, and the bolt 28 is inserted into the other opening 26 of the through hole 24.
Is mechanically fixed to the main body 22 by screwing the nut 30 to the other end 34 of the main body.

In the volume increasing materials 8 and 20 shown in FIGS. 2 and 3, the pins 14 and the bolts 28 are respectively provided at the openings at both ends of the through holes 12 and 24 of the main bodies 10 and 22, respectively. One end is locked by abutment against one opening and the other end is mechanically engaged at the other opening by suitable engagement means. From where they are,
These are exposed to the openings at both ends of the through holes 12 and 24 of the main bodies 10 and 22, respectively, and thereby, in addition to the effect of increasing the magnetic attraction force by adopting the elongated core (pin 14, bolt 28). Further, it is possible to exert a more effective magnetic force without increasing the magnetic force of the magnetic separation device or the like, and the separation / recovery operation can be easily performed.

Further, the volume increasing materials 8 and 2
Reference numeral 0 denotes a structure in which the pins 14 and the bolts 28 are mechanically attached to the ceramic bodies 10 and 22 obtained as an integrally molded (fired) body. Unlike the structure in which the ceramics body is integrally fixed by an adhesive or the like, even when the volume increasing materials 8 and 20 are subjected to an impact during separation / recovery work or the like, the ceramic body is Breakage is significantly reduced, which can improve the life of the volume increasing material and reduce the cost of the volume increasing material itself, thereby lowering the casting cost in a mold using such a volume increasing material. Can also be advantageously achieved.

In the volume increasing material according to the present invention, the outer diameter of the ceramic body and the diameter and length of the rod-shaped core are appropriately set according to the applied mold. The outer shape thereof may be any shape as long as it has a substantially spherical shape, such as a perfect circular shape or an elliptical shape, and the shape of the rod-shaped core may be a solid or hollow columnar shape. A shape such as a prismatic shape can be appropriately selected.

Further, the volume-increasing agent according to the present invention, the ceramic body (4) is rod-shaped core body (6) thereof
By firing in the state of being inserted into the through hole ,
Even in the case of an integral structure, a predetermined core (14, 22) is formed in a through hole (12, 24) using a body (10, 22) of a desired shape obtained by firing. , 2
8), the main body (1) is inserted by appropriate mechanical engagement.
0, 22), any of them can be suitably adopted. In addition,
In the latter case, the through-hole can be formed at the same time as the press molding of the main body, or can be formed after firing.

The volume-increasing material according to the present invention having such a long rod-shaped core can be manufactured, for example, as follows. First, a ceramic powder raw material obtained by adding 20% of alumina to mullite is blended for press molding, and this is used to form a rod-shaped core (14) made of a magnetic material from the outside after molding as shown in FIG. An elliptical ceramic body (10) having a through hole (12) through which it can be inserted is press-formed. Thereafter, drying is performed in accordance with a usual method, and a baking operation is performed at a predetermined temperature and time to obtain a ceramic body (10) having a desired shape having a short diameter of 30 mmφ and an oblong diameter of 35 mmφ. You get it. The firing temperature and time in the firing step are appropriately determined according to the components of the ceramic used.

Next, SS41 produced in another step
Using a 6 mmφ rod-shaped core material (14) made of a material, the through hole (1) of the ceramic body (10) obtained above
2) by inserting the one end (16) into the opening of the through hole (12) and fixing the other end (18) by caulking according to a conventional method. Thus, the intended volume increasing material (8) in which the rod-shaped core material (14) is arranged to extend in the longitudinal direction at the center of the main body (10) is obtained.

The volume-increasing material according to the present invention manufactured in this manner can be used in any of various molds obtained by molding a predetermined molding sand, instead of the molding sand behind the skin sand layer. Can be advantageously employed.

Although the specific configuration of the present invention has been described in detail with reference to the drawings, the present invention is not limited by the above description.
In addition, in addition to the above specific description, various changes, modifications, improvements, etc. based on the knowledge of those skilled in the art can be added to the present invention without departing from the spirit of the present invention. It should be understood.

The volume increasing material according to the present invention is as follows.
In any of the various conventional molds, it can be used in place of the foundry sand behind the sand layer, thereby advantageously reducing the S / M ratio of the mold. In particular, it is suitably used for a mold molded using an organic self-hardening molding sand, and can exhibit its characteristics more remarkably.

[0023]

As is apparent from the above description, in the volume increasing material according to the present invention, a solid or hollow long rod-shaped core made of a magnetic material is attached to a ceramic body of a predetermined size. It is configured to be inserted and placed in the through hole of
This volume increasing material is separated magnetically from casting sand.
At the time of recovery, it is possible to sufficiently exhibit magnetic adhesion without requiring an increase in magnetic force for separation and recovery,
Thus, the cost of the magnetic separation device can be effectively reduced, the size of the volume increasing material can be changed relatively freely, and the cost per unit volume can be reduced.

[0024] Moreover, in the present invention, the rod-shaped core is disposed so as to penetrate through the ceramic body, with its both end portions are exposed, are mechanically crimped engagement fit ceramic body from where, the impact resistance of a volume increasing agent, thus in addition to the service life can be advantageously improved, magnetic attraction force is remarkably strong for the exposed portions of the rod-shaped core both ends, whereby, separation and recovery by magnetic The work can be performed even more advantageously.

[Brief description of the drawings]

FIG. 1 is an explanatory cross-sectional view showing an example of a volume increasing material which helps understanding of the present invention.

FIG. 2 is an explanatory sectional view showing an example of the volume increasing material of the present invention.

FIG. 3 is an explanatory sectional view showing another example of the volume increasing material of the present invention.

[Explanation of symbols]

 2 Volume increasing material 4 Main body 6 Rod core 8 Volume increasing material 10 Main body 12 Through hole 14 Pin 20 Volume increasing material 22 Main body 24 Through hole 28 Bolt 30 Nut

 ──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-2-220730 (JP, A)

Claims (1)

(57) [Scope of request for utility model registration] 1. A volume-enhancing material which is filled in place of a sand layer in a mold in place of a molding sand and is magnetically separated from the molding sand after casting, and comprises a solid or hollow longitudinal member made of a magnetic material. The rod-shaped core is inserted into a through hole provided in a ceramic body of a predetermined size .
With the arrangement, the rod-shaped
By mechanically engaging the ends of the core,
So as to prevent pulling out of the ceramic body
A volume increasing material for mold making characterized by being constituted .