KR101950923B1 - Filling material for saving molding sand and method for manufacturing the same - Google Patents

Abstract

The filler for the production of mold sand saving molds according to the present invention is formed so as to be filled between molding sands for molding, each of which comprises a plurality of spheres of metal with hollows , Each of the spheres may include a through hole communicating with the hollow.

Description

FIELD OF THE INVENTION [0001] The present invention relates to a filling material for the production of a casting mold saving mold,

FIELD OF THE INVENTION The present invention relates to a filling material for the production of a molding sand saving type mold and a method of producing the same.

Casting is a method of making a product by injection and solidification into a mold in the shape of a molten metal to be heated. The casting process includes steps such as planning, prototyping, molding, melting, injection, post-processing and inspection. The production of double molds has advantages and disadvantages depending on the quantity of production, the size of product, the existence of basic equipments, economical efficiency, and requires much experience and skill, and it takes the most time during casting process. Molding cost and molding time for mold production have the greatest effect on production cost.

A sand mold is a sand used to make a mold. In general, molding sand is used as a main component of a granite to provide moldability and strength.

Castings formed by molding sand have gaps between the particles, and fire resistance may decrease due to the addition of a binder or an additive. Therefore, the mold surface may be coated with a mold agent to fill the mold surface.

The foundry is aging as it is repeatedly used. The main constituent of the foundry sand is silica sand and clay. It is typical that the granite is collapsed or thinned due to heat, and the clay loses its point strength. In addition, the aging of the foundry involves the incorporation of metal oxides. The regeneration process of the foundry sand is to restore the lower quality as the number of times of use of the foundry sand becomes larger. The regeneration process of the foundry sand has a local treatment method for treating only foundry sand near the casting product and a whole treatment for treating all the sand used in the mold.

The sand / metal ratio to the unit weight of the product determines the casting productivity and manufacturing cost. Generally, it is about 6: 1 for green sand mold casting, hard casting such as Furan, and forged casting such as CO ₂ . Since the saving of molding sand can increase the production cost competitiveness by casting, technology for saving the molding sand has been suggested.

Related Prior Art:

1. Korean Registered Patent No. 10-0197389 (issued June 15, 1999)

2. Japanese Patent No. 3122837 (issued on October 27, 2000)

3. Japanese Patent Laid-Open No. 2000-254757 (published on September 19, 2000)

4. Japanese Patent Laid-Open No. 2001-179393 (published on Mar. 3, 2001)

It is an object of the present invention to provide a filler for the production of a casting mold saving mold having excellent mass productivity and structural stability from handling and the like and a production method thereof.

In order to solve the above problems, a filler for the production of a molding sand saving type mold according to the present invention is formed so as to be filled between molding sand for molding, each of which is made of a metal having hollow A plurality of spheres of material, and each of the spheres may include a through hole communicating with the hollow.

In one embodiment of the present invention, the through holes are formed as a pair, and the pair of through holes may be arranged symmetrically with respect to the center of the sphere.

As an example related to the present invention, the spheres may be formed of iron-based materials.

As an example related to the present invention, the filler may further include irregularities formed on the surface of the sphere and formed to prevent slip between the spheres.

As an example related to the present invention, the irregularities may be formed in a shape including protrusions protruding from the surface of the spherical body.

As an example related to the present invention, the diameter (D) of the spheres may be 15 to 200 mm.

As an example related to the present invention, the thickness t of the spheres may be 1 to 10 mm.

In one embodiment of the present invention, the width w of the through-hole may be 1/15 to 1/5 of the diameter D of the spherical body.

The present invention also provides a method for manufacturing a filler made of a metal material having a hollow interior so as to be filled in between casting sand for molding, Disposing a bottom shell mold having a plurality of first lower molds formed thereon; A plurality of cores capable of forming a hollow of the filler and a core shell having a plurality of cores connected to each other by a core print so as to form a through hole for communicating the hollow, Placing; The lower surface of which is formed with a plurality of second lower molds so as to form a lower outer shape of the filler, Placing on top of the core shell; Alternately arranging and laminating the core shell and the intermediate shell mold; Disposing a cover shell mold on which a plurality of second upper mold sections are formed so as to form an upper outer shape of the filler on the top of the finally disposed core shell; Fixing the mold assembly of the laminated bottom shell mold, the core shell, the intermediate shell mold, and the cover shell mold, injecting and curing the melt; And removing the molding sand of the bottom shell mold, the core shell, the intermediate shell mold and the cover shell mold from the cured mold assembly.

In one embodiment of the present invention, the first upper half, the second upper half, the first lower half, and the second lower half have a plurality of recesses formed therein so that a plurality of projections can be formed on the surface of the filler .

According to the filling material for manufacturing casting mold saving type molds and the manufacturing method thereof related to the present invention, the filling material is constituted by using spheres of metal having a hollow, and the use of molding sand used in casting can be remarkably reduced. Spheres of metal having hollow are easy to recover and can be continuously used by reuse.

The filler associated with the present invention has a through-hole communicating with the hollow, so that manufacture through the casting process can be suitably used, thereby facilitating securing the necessary rigidity with the volume required as filler.

According to the method for producing a filler related to the present invention, a metal spherical body having a through-hole communicating with the hollow body can be mass-produced at one time by using a bottom shell mold, a core shell, an intermediate shell mold having shapes on both sides, have. The filler using such a shell mold is advantageous in that it has high dimensional stability and a uniform surface.

According to one embodiment of the present invention, by forming projections and recesses in the form of projections on the surface of the filler, it is possible not only to prevent slip between the spheres, but also to minimize the contact area with the melt in the molding process, And chilling of the casting product can be minimized.

FIGS. 1 to 6 are cross-sectional views illustrating a method for manufacturing a filler material for manufacturing a molding sand saving type mold according to an embodiment of the present invention,
Figure 1 shows a bottom shell mold 110,
FIG. 2 illustrates the process of laminating the core shell 120 to the bottom shell mold 110,
FIG. 3 shows that the intermediate shell mold 130 is laminated in FIG. 2,
Figure 4 shows a stacked shell mold assembly 100 with lamination completed,
5 illustrates injecting molten metal M into stack shell mold assembly 100,
FIG. 6 shows a degassing process of the stack shell mold assembly 100 'in which the molten metal is injected and molded.
Figure 7 is a cross-sectional view of a filler product 200 for the production of a mold sand saving mold in accordance with the present invention.
8 is a cross-sectional view conceptually showing a mold being manufactured using the filler product 200 according to the present invention.
9 is an enlarged view of a portion of the filler product 200 in FIG.
10 is a cross-sectional view of another filler product 200 'in another example related to the present invention.
11 is a cross-sectional view partially showing the state of the mold being manufactured using the filler product 200 'of FIG.

Hereinafter, a filler for manufacturing a casting mold saving mold and a method of manufacturing the same according to the present invention will be described in detail with reference to the accompanying drawings.

The fillers related to the present invention are formed so as to be able to be filled between molding sand for molding, each of which is in the form of a plurality of spheres of a metal having a hollow inside. Each of these spheres has a through-hole communicating with the hollow. The filler can be applied to sand casting molds and specifically includes greensand casting, hard casting such as Furan, solvent casting such as CO ₂ , shell mold or stack mold ) Casting can also be used. The hollow sphere may be formed of an iron-based material. Hereinafter, a method for producing a filler will be described, and then a technique for producing a mold using the filler produced thereby will be described.

FIGS. 1 to 6 are cross-sectional views illustrating a method for manufacturing a filler material for manufacturing a molding sand saving type mold according to the present invention.

As shown in FIG. 1, a bottom shell mold 110 having a plurality of first lower mold parts 115 formed therein so as to form a lower outer shape of the filler is disposed. The bottom shell mold 110 can be formed into a thin shell-like shell by heat-curing a synthetic silica containing dry sand and sizing resin having a particle size of about 40 to 140 mesh at 200 to 300 ° C. These shell molds are advantageous in terms of mass productivity, excellent surface accuracy and saving of molding sand.

2 shows laminating the core shell 120 on top of the bottom shell mold 110. The core shell 120 has a plurality of cores 121 capable of forming a hollow of a filler, and each of the cores 121 is connected by a core print 125. The core print 125 is also a portion forming a through hole for communicating the hollow of the filler to be manufactured with the outside.

The core shell 120 can be manufactured by thermally curing a synthetic fiber including dry sand and resin binder, as in the case of the bottom shell mold 110. 3) is formed between the lower surface of the core 121 and the surface of the first lower mold portion 115 when the core shell 120 is disposed on the upper portion of the bottom shell mold 110. [ In the cavity C, a portion to be filled with the molten metal in a step to be described later forms a thickness of the filler.

Next, as shown in FIG. 3, an intermediate shell mold 130 is disposed on the core shell 120. A plurality of first upper mold parts 135 are formed on the lower surface of the intermediate shell mold 130 so as to form an upper outer shape of the filler. The upper portion 136 may be formed. The intermediate shell mold 130 can also be produced by thermosetting a synthetic fiber comprising dry sand and resin binder. Since the intermediate shell mold 130 holds the upper part of the upper mold and the lower part of the lower mold at the same time, mass production can be induced by laminating them. That is, the core shell 120 and the intermediate shell mold 130 are alternately arranged and laminated.

As shown in FIG. 4, a cover shell mold 140 having a plurality of second upper mold parts formed therein is disposed on the top of the finally disposed core shell 120 so as to form an upper outer shape of the filler. The cover shell mold 140 may be provided with a sprue 151 and a riser 152.

The stacked bottom shell mold 110, the core shell 120, the intermediate shell mold 130 and the cover shell mold 140 are fixed by means such as a clamp to prevent the gap from spreading, do.

As shown in FIG. 5, the molten metal M is injected into the prepared mold assembly 100 and then solidified by cooling.

6 is a conceptual diagram illustrating the process of desorbing the molding sand of the bottom shell mold 110, the core shell 120, the intermediate shell mold 130 and the cover shell mold 140 from the mold assembly 100 in which the molten metal M is hardened. . A dressing device 160 may be used to remove the foundry sand. The dressing device 160 may include a drum to be rotated. During the rotation of the drum, the molding sand S is separated from the filler product 200 by falling and mutual collision in the drum. A vibration device or the like may be used for easy removal of the molding sand constituting the core 121 inside the filler product 200.

Figure 7 is a cross-sectional view of a filler product 200 for the production of a mold sand saving mold in accordance with the present invention.

The metal spheres 201 constituting the filler product 200 include the hollow 202 and the hollow 202 is communicated with the outside by the through hole 203. This through hole 203 is formed by the core print 125, through which the molding sand of the core 121 inside the molded body 201 is recovered.

The through holes 203 are formed in a pair, and they may be disposed symmetrically with respect to the center of the sphere 201. The diameter (D) of the sphere 201 may be 15 to 200 mm so as to obtain an effect of reducing the casting sand yarn substantially. The thickness t of the sphere 201 may be 1 to 10 mm in consideration of the stability from the deformation or thermal deformation during handling and the structural stability due to the pressure.

The width of the through hole 203 is set to be smaller than the width of the sphere 201 so that the casting yarn can be easily recovered in the manufacturing process of the sphere 201, ) Of the diameter D of the first and second electrodes.

FIG. 8 is a cross-sectional view conceptually showing a mold being manufactured using the filler product 200 according to the present invention, and FIG. 9 is an enlarged view of a filler product 200 portion in FIG.

The manufactured filler product 200 can replace the space in which the molding sand 230 is to be filled during the production of the mold. That is, when the mold 220 is placed on the mold 210 and the molding sand 230 is filled, a mixture of the molding sand 230 and the filler product 200 may be injected into the mold 210 to fill the space. The casting yarn 230 may be introduced into the hollow 202 in the filler product 200 through some of the through holes 203. However, due to the characteristics of the powder, the amount of the molding sand 230 flowing into the through-hole 203 is relatively small and it is also easily removed through the through-hole 203 again.

FIG. 10 is a cross-sectional view of another filler product 200 'according to another embodiment of the present invention, and FIG. 11 is a cross-sectional view partially showing the state of a mold being manufactured using the filler product 200' of FIG.

In this example, it is seen that the surface of the sphere 201 has irregularities. This unevenness not only prevents the slip between the spheres 201 in filling and compaction of the foundry sand, but also minimizes direct exposure of the surface of the sphere 201 to the mold inner wall 221, It is possible to minimize the chill of the product. The irregularities may be formed in the form of protrusions 205 protruding from the surface of the sphere 201. In this case, on the surface of the sphere 201, a plurality of (not shown) second upper and lower parts of the first upper part 135, the first lower part 115, the second lower part 136 and the cover shell mold 140, A plurality of recesses (not shown) may be provided so that the protrusions 205 of the protrusions 205 may be formed.

The filler for the production of the molding sand-saving mold as described above and the manufacturing method thereof are not limitedly applied to the construction and the method of the embodiments described. The embodiments may be configured so that all or some of the embodiments may be selectively combined so that various modifications may be made.

100: stack shell mold assembly 110: bottom shell mold
115: first lower mold part 120: core shell
121: core 125: core print
130: intermediate shell mold 135: first upper mold half
136: second lower mold top 140: cover shell mold
151: sprue 152: riser
160: desizing device
200, 200 ': Filler for the production of molding sand saving molds
201: metal spheres 202: hollow
205: Projection 210:
220: mold 221: mold inner wall
230: Foundry C: Cavity
M: Molten metal S: Sieve separated from product

Claims (10)

A plurality of spheres made of metal having hollows, each of which is formed so as to be filled between molding sands for molding,
The spheres are formed of an iron-based material,
Each of the spheres,
And a through hole communicating with the hollow,
A concavo-convex surface is formed on the surface of the spherical body so as to prevent slip between the spherical bodies,
Wherein the irregularities comprise a plurality of projections spaced apart along the surface of the sphere.
The method according to claim 1,
Wherein the through holes are in a pair and the pair of through holes are disposed symmetrically with respect to the center of the sphere.
delete delete delete The method according to claim 1,
Wherein the spheres have a diameter of 15 to 200 mm.
The method according to claim 1,
Wherein the spheres have a thickness of 1 to 10 mm.
The method according to claim 1,
And the width of the through-hole is 1/15 to 1/5 of the diameter of the spherical body.
A method of manufacturing a filler made of a metal material having a hollow inside so as to be filled between casting sand for molding,
Disposing a bottom shell mold in which a plurality of first lower mold portions are formed to form a lower outer shape of the filler;
A plurality of cores capable of forming a hollow of the filler and a core shell having a plurality of cores connected to each other by a core print so as to form a through hole for communicating the hollow, Placing;
The lower surface of which is formed with a plurality of second lower molds so as to form a lower outer shape of the filler, Placing on top of the core shell;
Alternately arranging and laminating the core shell and the intermediate shell mold;
Disposing a cover shell mold on which a plurality of second upper mold sections are formed so as to form an upper outer shape of the filler on the top of the finally disposed core shell;
Fixing the mold assembly of the laminated bottom shell mold, the core shell, the intermediate shell mold, and the cover shell mold, injecting and curing the melt; And
And removing the foundry sand of the bottom shell mold, the core shell, the intermediate shell mold and the cover shell mold from the cured mold assembly.
10. The method of claim 9,
Wherein a plurality of recesses are formed in the first upper part, the second upper part, the first lower part and the second lower part so that a plurality of projections can be formed on the surface of the filler, A method for producing a filler for a thermoplastic resin composition.

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