KR102086322B1 - Method of manufacturing salt core - Google Patents

Abstract

The present invention relates to a method for manufacturing a salt core which is inserted into a cavity during molding. To this end, the present method is characterized by comprising: a first step in which data of a plurality of salt core layers are prepared by dividing a salt core to be molded by a predetermined unit height from a lower surface and making the same into data; a second step in which industrial salt is dissolved or dispersed in water or an organic solvent to manufacture a salt ink; a third step in which, according to the data of a first salt core layer among the data of the plurality of salt core layers, the salt ink is vertically sprayed on a printing pad while the position of an inkjet head is controlled along an x axis and a y axis on a horizontal surface from an upper portion of the heated printing pad whose height can be adjusted, thereby forming the first salt core layer; and a fourth step in which the third step is repeatedly and individually performed according to the data of the remaining salt core layers among the data of the plurality of salt core layers while the printing pad is descended by the unit height in order to form the plurality of stacked salt core layers, thereby completing formation of the entire salt cores. Therefore, provided is the method for manufacturing a salt core, which can guarantee freedom in shape embodiment and facilitate ease of removal after molding.

Description

Salt core manufacturing method {METHOD OF MANUFACTURING SALT CORE}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a core inserted into a cavity during casting, and more particularly, to a method for producing a salt core made of industrial salt.

A common core using sand and resin has a problem that it is easily broken in the use environment of the high pressure casting method in which molten metal is filled into the cavity at high speed and high pressure, and a salt core has been developed to solve this problem. .

Salt cores have the advantage that they are effective in forming cores from molten salt and can be removed by dissolving the salt cores remaining in the casting after casting. It is difficult to realize the shape, and since the core is made of molten salt, it is difficult to dissolve in water when the tissue is dense and remain in the mold after casting. In addition, there was a problem that the salt core remaining in the casting by secondary sintering by molten metal is not easily dissolved in water.

Prior Art Documents Korean Laid-Open Patent No. 10-2018-0085483 (Publication date: July 27, 2018)

Accordingly, an object of the present invention is to provide a salt core manufacturing method that ensures freedom of shape implementation and is easy to remove after casting.

In order to achieve the above object, the present invention provides a salt core manufacturing method comprising the steps of preparing a plurality of salt core layer data by dividing the salt core to be formed into a predetermined unit height from the bottom surface; Preparing a salt ink by dissolving or dispersing industrial salt in water or an organic solvent; According to the first salt core layer data of the plurality of salt core layer data, the inkjet head is vertically positioned on the printing pad while the inkjet head is positioned on the horizontal plane in the x and y axes on the height-adjustable heated printing pad. Forming a first salt core layer by spraying the salt ink; And repeating the third step according to the remaining salt core layer data of the plurality of salt core layer data while lowering the printing pad by the unit height to form a plurality of stacked salt core layers. It provides a salt core manufacturing method comprising a fourth step of achieving the molding of.

Here, in the third step, the salt ink may be sprayed only to the edge region of the first salt core layer to be molded to a predetermined thickness, and the salt ink injection may be omitted for the inner region except the edge region.

As described above, according to the salt core manufacturing method according to the present invention, a total salt core can be obtained by stacking a plurality of salt core layers in a 3D printing method using an inkjet head that sprays salt ink on a printing pad. The shape can be easily implemented. Therefore, it is possible to implement only the manufacturing method of the 3D printing method for a single salt core of the combined shape of all the cores in place of the conventional method of manufacturing a complex core by bonding the five to seven cores.

In addition, the inkjet spraying technique enables the production of salt cores of relatively low density, making salt cores easily soluble in water. Furthermore, a low density salt core can be manufactured by spraying salt ink only to the edge region of the core to form a predetermined thickness, and for this reason, a salt core that can be easily dissolved in water can be manufactured.

1 is a plan view of a salt core manufacturing apparatus used in the salt core manufacturing method according to an embodiment of the present invention,
FIG. 2 is a schematic view illustrating a manufacturing process of the salt ink used in the salt core manufacturing apparatus of FIG. 1; FIG.
3 is a cross-sectional view showing the formation of a salt core layer using the salt core manufacturing apparatus of FIG.
4 is a photograph of a salt core that may be obtained by performing the process of FIG. 3.

Salt core manufacturing method according to an embodiment of the present invention is carried out using the salt core manufacturing apparatus 100 of FIG. The salt core manufacturing apparatus 100 includes a printing pad 110 through which salt ink is injected, and an inkjet head 123 capable of position control in a horizontal plane by a main shaft 121 and a movable shaft 122 thereon. .

The printing pad 110 is provided to be able to adjust the height (see FIG. 3) and is also provided to maintain the temperature of the pad as a hot plate at 70 ° C. to 200 ° C. FIG.

Salt ink, which is a raw material of the inkjet head 123, is mixed by pouring an organic solvent or water into a container containing the industrial salt 1, as shown in FIG. It is prepared in dissolved or dispersed form.

The inkjet head 123 for ejecting the salt ink can produce a salt core having a critical density by controlling the size and ejection speed of the droplet using a piezoelectric element, and the inkjet nozzle as the inkjet head 123 is a single jet The thickness of 10 ~ 50㎛, in the case of the dispenser nozzle can implement a thickness of 100 ~ 300㎛.

The printing pad 110 maintained at 70 to 200 ° C. is for rapidly drying water or an organic solvent in the salt ink sprayed on the surface. In order to increase the drying effect, a method of increasing the room temperature by implementing the upper space of the printing pad 110 obtained by stacking the salt cores 2 as a chamber (not shown) in FIG. 3 may be employed.

Meanwhile, the salt core layer data is prepared in advance for a plurality of salt core layers obtained by dividing the salt core to be formed by the unit height h from the salt core to be molded using the salt core manufacturing apparatus 100.

Accordingly, an inkjet head (not shown) may be formed on the printing pad 110 using the main shaft 121 and the movable shaft 122 of FIG. 1 according to the first salt core layer data forming lower ends of the plurality of salt core layer data. 123 is sprayed with the salt ink vertically toward the printing pad 110 while positioning the x and y axes on the horizontal plane. In this way, the integrated first salt core layer is formed by performing salt ink spraying on all the first salt core layers in a planar manner.

As such, when the forming of the first salt core layer is completed, the printing pad 110 of FIG. 3 descends by the unit height h, and the second salt core forming the second layer from the lower ends of the plurality of salt core layer data. According to the layer data, the inkjet head 123 is vertically salted toward the printing pad 110 while the inkjet head 123 is positioned on the x and y axes on a horizontal plane by using the main shaft 121 and the movable shaft 122 of FIG. 1. Spray ink. In this way, the second salt core layer integrally laminated on the first salt core layer is formed by spraying salt ink onto all of the second salt core layers in a planar manner.

The lamination molding of the salt core layer of the above-described method is repeatedly performed for each salt core layer, as shown in FIG. 3, and is completed by forming all the salt core layer data forming the salt core to be formed. Molding of the salt core is achieved.

The salt core thus formed may be implemented as a salt core 3 having a complicated shape as shown in FIG. 6. In order to manufacture the salt core 3 according to the prior art, it was possible to achieve by integrating through the process of dividing into four divisions or more, and then bonding each other.

On the other hand, the stacked salt core layer obtained by the salt ink injection as described above is less compact than the structure of the salt core obtained by compression and melting using a mold according to the prior art has the advantage that it is more easily dissolved in water after casting, In order to perform the salt core removal operation more smoothly, a portion where the salt ink is sprayed during the formation of the salt core layer may be limited to an edge region of the salt core layer.

For example, referring to FIG. 3, the salt core layer 2a which sprays to the inkjet head 123 is limited to the edge portions 2b and 2c. The salt core 2 has only a thickness thereof by performing salt ink injection only to a predetermined width inward from the edge portions 2b and 2c. In this case, since the salt ink injection is omitted from the outer surface of the salt core 2 to a predetermined thickness, the hollow salt core 2 can be realized. Thus, saltcores fabricated in this way can produce saltcores of much lower density and are readily soluble in water.

On the other hand, since the salt core manufacturing method described above is only one embodiment for aiding the understanding of the present invention, the scope of the present invention, which is defined by the claims and equivalents described below, is set forth above. It is not limited.

1: industrial salt
2: saltcore
2a: saltcore layer
2b, 2c: rim
3: saltcore
100: salt core manufacturing apparatus
110: printing pad
121: main shaft
122: movable shaft
123: inkjet head

Claims (2)

In the salt core manufacturing method,
A first step of preparing a plurality of salt core layer data by dividing the salt core to be formed into data by dividing the salt core from a bottom into a predetermined unit height;
Preparing a salt ink by dissolving or dispersing industrial salt in water or an organic solvent;
According to the first salt core layer data of the plurality of salt core layer data, the inkjet head is positioned vertically on the printing pad while the inkjet head is positioned on the horizontal plane in the x and y axes on the height-adjustable heated printing pad. Forming a first salt core layer by spraying the salt ink; And
While the printing pad is lowered by the unit height, the third step is repeated according to the remaining salt core layer data of the plurality of salt core layer data to form a plurality of stacked salt core layers. And a fourth step of achieving molding. The method of claim 1,
The third step,
And forming a predetermined thickness by spraying the salt ink only on the edge region of the first salt core layer, and omitting the salt ink on an inner region except the edge region.

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