WO2024262667A1 - Filtering apparatus for differential pressure casting equipment - Google Patents

Abstract

Provided is a filtering apparatus for differential pressure casting equipment, comprising, so as to effectively remove foreign material generated in a mold during casting: a base plate for forming the bottom thereof; vertical shafts vertically provided on the base plate; a fixed plate provided at the tops of the vertical shafts so as to support the vertical shafts; a worktable which can vertically slide along the vertical shafts and which has a lower die provided thereabove; a movable plate which is disposed above the worktable so as to vertically slide along the vertical shafts, and which has an upper die provided therebelow; a vertical driving part provided on the fixed plate, and connected to the movable plate in order to vertically move the movable plate; a heat-retaining furnace disposed on the base plate, and connected to the worktable so as to supply molten metal to the mold; a stoker, which connects the heat-retaining furnace and the mold so as to supply the molten metal of the heat-retaining furnace to the mold; a pressure part, which applies differential pressure to the heat-retaining furnace and the mold so as to inject the molten metal into the mold; and a filtering part connected to the mold so as to remove foreign material generated in the mold.

Description

Filtering device of pressure casting equipment

The present disclosure relates to a filtering device for a pressure casting facility.

Recently, differential pressure casting equipment has been widely used in casting aluminum wheels for automobiles, cylinder heads for engines, housings, etc.

A differential pressure casting device may include a holding furnace for receiving molten metal, a mold positioned above the holding furnace and connected to the holding furnace through a stock, and a pressure section for applying pressure to the holding furnace and the mold to fill the molten metal into the mold by differential pressure.

Accordingly, by applying the same pressure to the furnace and the mold and then applying differential pressure so that the pressure inside the mold is relatively low, the molten metal is filled inside the mold. As the molten metal rises and fills inside the mold due to the differential pressure, the occurrence of turbulence can be minimized.

When the mold is filled with molten metal, the molten metal is solidified by maintaining the pressure for a certain period of time. When solidification is complete, the pressure is removed, the mold is opened, and the casting is separated, thereby completing the product casting. When the casting is separated, the unsolidified molten metal on the stock side can be recovered to the holding furnace. When the product casting is complete, the height of the melt surface in the holding furnace is lowered by the molten metal used, and the pressure can be corrected to the corresponding pressurization conditions when casting the next product.

However, in the case of conventional differential pressure casting equipment, there is a problem in that foreign substances generated within the mold cannot be processed. The core provided within the mold is formed into a desired shape by mixing bonds or additives with sand for casting, but when these bonds or additives burn due to high temperature, foreign substances such as dust and gas are generated.

These foreign substances need to be removed because they lower the quality of the product or cause defective products. However, due to the characteristics of differential pressure casting equipment, exhaust does not occur while the mold is under pressure, so it was difficult to remove foreign substances generated inside the mold during the casting process.

This project is to provide a filtering device for a differential pressure casting facility that can effectively remove foreign substances generated in a mold during casting.

The present invention relates to a filtering device for a differential pressure casting facility capable of removing foreign substances while maintaining pressure within a mold and preventing pressure loss.

The differential pressure casting equipment of the present embodiment may include a base plate forming a floor, a vertical shaft installed vertically on the base plate, a fixed plate installed on the upper portion of the vertical shaft to support the vertical shaft, a work table installed so as to be able to slide up and down along the vertical shaft and having a lower die installed on the upper portion, a movable plate disposed on the upper portion of the work table to slide up and down along the vertical shaft and having an upper die installed on the lower portion, a vertical driving unit installed on the fixed plate and connected to the movable plate to move the movable plate up and down, a holding furnace disposed on the base plate and connected to the work table to supply molten metal to a mold, a stock connected between the holding furnace and the mold to supply molten metal from the holding furnace to the mold, a pressure unit that applies differential pressure to the holding furnace and the mold to inject molten metal into the mold, and a filtering unit connected to the mold to remove foreign substances generated in the mold.

The above pressure casting equipment may further include a clamping unit that selectively connects the movable plate and the work table to raise the work table when moving to the heating furnace.

It may further include an ejection unit installed on the above movable plate to separate the casting from the mold.

The above vertical driving unit may include a vertical cylinder that is installed vertically on a fixed plate and connected to the movable plate to move a work table connected to the movable plate up and down.

The above pressure unit may include a pressurized gas storage tank for applying gas pressure to a surface of the molten metal, an injection line for injecting the pressurized gas of the storage tank into the mold and the interior of the heating furnace, a pressure regulator installed in each of the injection lines, and a control unit for controlling the pressure regulator to control the gas pressure inside the mold and the heating furnace.

The above mold is provided on the work table and may include a lower mold connected to the stock and an upper mold positioned above the lower mold.

The above mold can form a plurality of cavities between the lower mold and the upper mold and the lower mold, including a side mold arranged on the side of the lower mold.

The above casting device may have a plurality of stocks, and an injection port connected to each cavity and through which molten metal is injected may be structured to be connected to at least one stock to receive the molten metal.

The above filtering unit may include a circulation line branched from the exhaust line of the mold and connected to the inside of the mold to circulate gas inside the mold, a circulation valve installed in the circulation line to selectively open and close the circulation line according to a signal from the control unit, and a filter unit connected to one side of the circulation line to remove foreign substances from gas moving along the circulation line.

An exhaust valve that selectively opens and closes the exhaust line is installed in the above exhaust line, and the purification line may have a structure that is connected to the exhaust line at a position between the exhaust valve and the mold.

The above filtering part may further include a check valve installed between the filtering part and the mold to block reverse flow of gas to the circulation line.

The above filtering unit may further include a gas transfer pump installed on one side of the circulation line to induce the flow of gas inside the mold into the circulation line.

The above filter unit may include a housing having an inlet and an outlet through which gas passes, and plates arranged in a zigzag shape staggered inside the housing to reduce the flow speed of the gas and separate foreign substances from the gas.

The above filter unit may further include a filter membrane arranged at the rear end of the grid plate to filter out foreign substances contained in the gas.

According to this embodiment, foreign substances can be removed by discharging the gas inside the mold while maintaining the internal pressure of the mold. Accordingly, the differential pressure casting process can be properly performed while preventing pressure loss and removing only foreign substances generated inside the mold.

Foreign substances generated inside the mold during the differential pressure casting process can be effectively removed, allowing the free use of various sand mold cores without the influence of foreign substances.

This prevents product quality degradation caused by foreign substances and enables the production of a variety of high-quality castings.

FIG. 1 is a schematic drawing of a differential pressure casting facility according to the present embodiment.

FIG. 2 is a schematic drawing showing a filtering device of a differential pressure casting facility according to the present embodiment.

FIG. 3 is a schematic cross-sectional view illustrating a filter section of a filtering device according to the present embodiment.

Hereinafter, embodiments of the present invention will be described in detail. However, these are presented as examples, and the present invention is not limited thereby, and the present invention is defined only by the scope of the claims described below. The embodiments described below can be modified in various forms without departing from the concept and scope of the present invention. Where possible, identical or similar parts are indicated using the same reference numerals in the drawings.

The terminology used below is for the purpose of describing specific embodiments only and is not intended to limit the invention. The singular forms used herein include the plural forms as well, unless the context clearly dictates otherwise. The word “comprising,” as used herein, specifies particular features, regions, integers, steps, operations, elements, and/or components, but does not exclude the presence or addition of other particular features, regions, integers, steps, operations, elements, components, and/or groups.

Hereinafter, preferred embodiments of the present invention will be described. However, the following embodiments are only preferred embodiments of the present invention, and the present invention is not limited to the following embodiments.

Hereinafter, this embodiment will be described using a differential pressure casting facility as an example. This device can be applied to all casting facilities having a structure that applies and maintains a certain pressure inside a mold in addition to a differential pressure casting facility.

Figure 1 schematically illustrates a differential pressure casting facility equipped with a cooling device according to the present embodiment.

As shown in Fig. 1, the differential pressure casting facility (100) includes a frame structure including a base plate (110) forming a floor, a vertical shaft (112) installed vertically on the base plate (110), a fixed plate (114) installed on the top of the vertical shaft (112) to support the vertical shaft (112), a work table (120) installed so as to be able to slide up and down along the vertical shaft (112) and having a lower die (152) installed on the top, a movable plate (130) positioned on the top of the work table (120) to slide up and down along the vertical shaft (112) and having an upper die (154) installed on the bottom, a vertical drive unit (140) installed on the fixed plate (114) and connected to the movable plate (130) to move the movable plate (130) up and down, an ejection unit (160) installed on the movable plate (130) to separate a casting from a mold (150), It may include a heating furnace (180) arranged on a base plate (110) and connected to a work table (120) to supply molten metal to a mold (150), a stock (172) connecting the heating furnace (180) and the mold (150) to supply molten metal from the heating furnace (180) to the mold (150), a pressure unit (not shown) that applies differential pressure to the heating furnace (180) and the mold (150) to inject molten metal into the mold (150), and a filtering unit that is connected to the mold and removes foreign substances generated in the mold.

The mold (150) is for forming a casting by introducing molten metal, and may include a lower mold (152) and an upper mold (154) arranged vertically. The mold (150) may further include a side mold arranged laterally. When the lower mold (152) and the upper mold (154) or the side mold are interlocked with each other, a cavity, which is a space according to the shape of the casting, is formed inside. The molten metal is injected into the cavity and formed into a casting. A core (not shown) may be further provided inside the mold (150) depending on the shape of the casting.

Hereinafter, the term “mold (150)” may refer to all of the upper and lower molds, side molds, and cores, or may mean a cavity, which is a space into which molten metal is injected.

The lower die (152) may be installed on the upper part of the work table (120) and connected to the heat-insulating furnace (180) through the stock (172). An injection port into which molten metal is injected may be formed on one side of the lower die (152). The molten metal may be supplied into the mold (150) through the stock (172) and the connecting pipe (170).

When a side mold is provided, a side mold and a horizontal cylinder (156) for horizontally moving the side mold may be further provided on the side of the work table (120). The side mold is arranged on the side of the lower mold, and may be divided into a plurality of parts and arranged along the circumference of the lower mold. The side mold is connected to the horizontal cylinder (156), and may be moved horizontally according to the operation of the horizontal cylinder (156) and may be engaged with the side between the upper mold and the lower mold.

The upper mold (154) can be installed at the bottom of the movable plate (130). The movable plate (130) is moved up and down by the vertical driving unit (140). As the movable plate (130) is moved up and down, the upper mold (154) installed on the movable plate (130) is engaged with or separated from the lower mold (152).

The mold (150) may further be provided with an inert gas supply means for the cavity, an air suction/discharge means, and an oxygen sensor. Accordingly, when pressurized supply of the molten metal is performed, the inert gas is supplied into the cavity and the air inside the cavity is sucked/discharged at the same time, thereby quickly replacing the inside of the cavity with an inert gas atmosphere.

The vertical driving unit (140) may include a vertical cylinder (142) installed on a fixed plate (114) and connected to a movable plate (130) to move the movable plate (130) up and down relative to the fixed plate (114). The movable plate (130) may be installed at the tip of a piston rod of the vertical cylinder (142). Accordingly, when the vertical cylinder (142) is elastically driven, the movable plate (130) moves up and down, and the upper die (154) installed on the movable plate (130) may engage with or be separated from the lower die (152).

The holding furnace (180) has a crucible (182) that holds molten metal inside. The holding furnace (180) maintains the molten metal in the crucible (182) at an appropriate temperature. The holding furnace may have a heat-retaining function to protect the crucible and prevent the molten metal held in the crucible from solidifying.

The stock (172) is connected to the injection port of the mold and functions as a passage for supplying molten metal to the mold. The lower end of the stock (172) is formed long enough to be immersed in the molten metal of the holding furnace and extends toward the bottom of the crucible. Accordingly, the molten metal contained in the crucible (182) can be supplied to the lower mold through the stock (172).

The pressure section applies differential pressure to the inside of the mold (150) and the furnace (180) to inject the molten metal into the mold.

For example, the pressure unit may include a pressurized gas storage tank for applying gas pressure to the inside of the heat insulating furnace (180) and the inside of the mold (150), an injection line for injecting pressurized gas from the storage tank into the inside of the heat insulating furnace (180) and the inside of the mold (150), a pressure regulator installed in each injection line, and a control unit for controlling the pressure regulator to control the gas pressure of each line.

The control unit adjusts the pressure inside the mold according to the differential pressure casting process. For example, the control unit can control and drive a pressure regulator to apply pressure to the inside of the mold or the inside of the holding furnace, or remove the pressure by exhausting the internal high-pressure gas, and form a differential pressure between the mold and the inside of the holding furnace.

As the pressure regulator operates, high-pressure gas is supplied to the mold and the heating furnace to control the pressure. The molten metal rises along the stock (172) due to the differential pressure between the heating furnace and the mold and is injected into the cavity of the mold (150).

When the molten metal is filled into the cavity, the mold is cooled while maintaining the pressure inside the holding furnace (180) at a constant level, thereby solidifying the molten metal inside the cavity. When the cooling is complete, the mold (150) is opened, and the solidified casting is ejected from the mold (150) by driving the ejection unit (160), thereby completing one process.

The mold (150) may further be provided with an exhaust line (190) for removing internal pressurized gas. An exhaust valve (192) for opening and closing the exhaust line (190) is installed on one side of the exhaust line (190). The exhaust valve (192) may be operated, for example, before opening the mold (150) after casting is completed to discharge the pressurized gas inside the mold (150).

The filtering part of this embodiment is provided in the mold (150) and removes foreign substances generated inside the mold (150) during casting.

Figures 2 and 3 illustrate the configuration of a filtering unit according to the present embodiment. Hereinafter, the filtering unit of the present embodiment will be described with reference to Figures 2 and 3.

As illustrated, the filtering unit of the present embodiment may include a circulation line (210) branched from the exhaust line (190) of the mold (150) and connected to the inside of the mold (150) to circulate gas inside the mold (150), a circulation valve (212) installed in the circulation line (210) to selectively open and close the circulation line (210) according to a signal from the control unit (200), and a filter unit (220) connected to one side of the circulation line (210) to remove foreign substances from gas moving along the circulation line (210).

Accordingly, when the pressure of the mold (150) rises and stabilizes and the circulation line (210) is opened during the process of injecting the molten metal, the gas inside the mold (150) flows into the circulation line due to the pressure difference. Accordingly, foreign substances such as dust generated by the high-temperature molten metal can flow into the circulation line (150) and be removed while passing through the filter unit (220).

The circulation line (210) may be installed in front of the exhaust valve (192) along the exhaust line (190). That is, as shown in FIG. 2, the circulation line (210) is connected to the exhaust line (190) at a position between the mold (150) and the exhaust valve (192). Accordingly, the exhaust line (190) may be connected to the circulation line (210) when the exhaust valve (192) installed in the exhaust line (190) is closed and blocks the exhaust line (190).

According to the signal from the control unit (200), the exhaust valve (192) is operated to block the exhaust line (190), and as the circulation valve (212) is opened, the exhaust line (190) is connected to the circulation line (210).

Accordingly, the gas inside the mold (150) can be continuously circulated into the mold (150) through the exhaust line (190) and the circulation line (210).

Since the circulation line (210) connects the exhaust line (190) and the mold (150), when the exhaust line (190) is closed and blocked, the gas inside the mold (150) does not escape to the outside through the circulation line (210). Accordingly, the pressure inside the mold (150) can be maintained as is.

That is, the inside of the mold (150) and the circulation line (210) are connected as one to form a closed space. The high-pressure gas inside the mold (150) can move to the circulation line (210), which is a connected space, but is not discharged to the outside of the mold (150). Therefore, the gas inside the mold (150) can be circulated through the circulation line (210) while preventing loss of pressure inside the mold (150).

Accordingly, foreign substances generated during casting of the mold (150) flow through the circulation line (210) together with the gas, and can be removed during this process by passing through the filter unit (220) installed in the circulation line (210). The clean gas from which the foreign substances have been removed is circulated back into the mold (150).

In this way, only foreign substances generated in the mold (150) can be removed without loss of internal pressure of the mold (150).

In this embodiment, the circulation line (210) may be provided separately from the exhaust line (190) and installed directly on the mold (150) in addition to a structure branched from the exhaust line (190) provided on the mold (150).

In addition, the filtering unit may further include a check valve (214) installed between the filter unit (220) and the mold (150) to block the backflow of gas to the circulation line (210). The check valve (214) allows the gas inside the mold (150) to flow only in the forward direction through the circulation line (210). The forward direction may mean the direction in which gas flows into the inlet side of the filter unit (220) and flows out through the outlet side.

Accordingly, when the circulation valve (212) is opened, the gas inside the mold can flow smoothly toward the filter unit (220) without flowing in the reverse direction. Accordingly, the high-pressure gas containing foreign substances can be passed through the filter unit (220) installed in the circulation line (210) and flow back into the mold (150) with the foreign substances removed.

In addition, the filtering unit may further include a gas transfer pump (216) installed on one side of the circulation line (210) to induce the flow of gas inside the mold (150) into the circulation line (210). By providing the gas transfer pump (216), the flow of gas inside the mold can be properly made to flow more forward.

The gas transfer pump (216) forces the high-pressure gas inside the mold (150) through the circulation line (210) while minimizing fluctuations in the pressure inside the mold (150). The gas transfer pump (216) can be applied to any structure capable of transferring gas.

By driving the gas transfer pump (216), the gas inside the mold (150) can be more smoothly guided forward and moved along the circulation line (210). Accordingly, the high-pressure gas can be continuously and smoothly moved through the circulation line (210) to remove foreign substances more effectively.

Figure 3 shows the structure of the filter unit (220) of this embodiment.

As illustrated, the filter unit (220) may include a housing (223) having an inlet (221) and an outlet (222) through which gas passes, and plates (224) arranged in a zigzag shape in an alternating manner inside the housing (223) to reduce the flow speed of the gas and separate foreign substances from the gas.

In addition, the filter unit (220) may further include a filter membrane (225) positioned at the rear end of the plate (224) to filter out foreign substances contained in the gas.

The housing (223) is connected to the circulation line (210) through an inlet (221) and an outlet (222) formed at each end of the housing (223). Accordingly, high-pressure gas moving through the circulation line (210) flows into the housing (223) through the inlet (221), passes through the housing (223), and is discharged through the outlet (222).

In a fixture where high-pressure gas passes through the housing (223), foreign substances contained in the high-pressure gas are separated and removed from the high-pressure gas.

The grating plate (224) guides the flow of high-pressure gas in a zigzag shape. The high-pressure gas slows down when it collides with the grating plates (224) arranged in a zigzag shape, and during this collision process, foreign matter particles with relatively large diameters and heavy substances fall and are separated from the high-pressure gas.

High-pressure gas, from which foreign substances are separated while primarily passing through the grating (224), can secondarily remove foreign substances while passing through the filter membrane (225) arranged on the outlet side of the housing (223).

The filter membrane (225) may be a membrane structure for filtering out fine particles. The filter membrane (225) can remove fine and light particles that are not separated from the plate (224).

Accordingly, all foreign substances contained in the high-pressure gas can be removed as they pass through the filter unit (220).

As it passes through the filter membrane (225), the clean high-pressure gas with foreign substances removed is reintroduced into the mold (150) through the circulation line (210).

As mentioned, the mold (150) and the circulation line (210) are connected as one, so even if high-pressure gas flows back into the mold (150), the pressure inside the mold (150) does not change.

Accordingly, casting can proceed normally while maintaining the set differential pressure regardless of the removal of foreign substances inside the mold (150).

In this way, by removing only foreign substances generated by sand cores, etc. inside the mold (150) while the internal pressure of the mold (150) is controlled in accordance with the differential pressure casting process, it is possible to manufacture a higher quality casting.

When the differential pressure casting is completed, the control unit (200) closes the circulation valve (212) installed in the circulation line (210) to block the circulation line (210). Then, according to the process, the exhaust valve (192) installed in the exhaust line (190) is opened to exhaust the high-pressure gas inside the mold (150).

The circulation line (210) is blocked, so the gas inside the mold (150) can be smoothly exhausted through the exhaust line (190).

While exemplary embodiments of the present invention have been illustrated and described above, it will be apparent to those skilled in the art that various modifications and other embodiments may be made thereto. It is intended that all such modifications and other embodiments be considered and encompassed by the appended claims and do not depart from the true spirit and scope of the present invention.

Claims (4)

A filtering device for a differential pressure casting facility, comprising: a base plate forming a floor; a vertical shaft installed vertically on the base plate; a fixed plate installed on the upper portion of the vertical shaft to support the vertical shaft; a worktable installed to be able to slide up and down along the vertical shaft and having a lower die installed on the upper portion; a movable plate disposed on the upper portion of the worktable to slide up and down along the vertical shaft and having an upper die installed on the lower portion; a vertical driving unit installed on the fixed plate and connected to the movable plate to move the movable plate up and down; a holding furnace disposed on the base plate and connected to the worktable to supply molten metal to a mold; a stock connected between the holding furnace and the mold to supply molten metal from the holding furnace to the mold; a pressure unit for applying differential pressure to the holding furnace and the mold to inject molten metal into the inside of the mold; and a filtering unit connected to the mold to remove foreign substances generated in the mold. In paragraph 1, A filtering device for a differential pressure casting facility, comprising: a circulation line branched from the exhaust line of the mold and connected to the inside of the mold to circulate gas inside the mold; a circulation valve installed in the circulation line to selectively open and close the circulation line according to a signal from a control unit; and a filter unit connected to one side of the circulation line to remove foreign substances from gas moving along the circulation line. In the second paragraph, A filtering device for a differential pressure casting facility, comprising: a housing having an inlet and an outlet through which gas passes; and plates arranged in a zigzag shape staggered inside the housing to reduce the flow speed of the gas and separate foreign substances from the gas. In the third paragraph, A filtering device of a differential pressure casting facility, wherein the filter section further includes a filter membrane arranged at the rear end of the grating to filter out foreign substances contained in the gas.

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