WO2014182045A1 - Double casting method and apparatus - Google Patents

Double casting method and apparatus Download PDF

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Publication number
WO2014182045A1
WO2014182045A1 PCT/KR2014/004016 KR2014004016W WO2014182045A1 WO 2014182045 A1 WO2014182045 A1 WO 2014182045A1 KR 2014004016 W KR2014004016 W KR 2014004016W WO 2014182045 A1 WO2014182045 A1 WO 2014182045A1
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WO
WIPO (PCT)
Prior art keywords
casting
mold
molten metal
cavity
casting chamber
Prior art date
Application number
PCT/KR2014/004016
Other languages
French (fr)
Korean (ko)
Inventor
지정욱
Original Assignee
Ji Jung Wook
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Ji Jung Wook filed Critical Ji Jung Wook
Priority to JP2016512831A priority Critical patent/JP6117992B2/en
Priority to US14/889,821 priority patent/US20160129498A1/en
Priority to CN201480038602.4A priority patent/CN105492143A/en
Priority to DE112014002341.8T priority patent/DE112014002341T5/en
Publication of WO2014182045A1 publication Critical patent/WO2014182045A1/en

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
    • B22D27/00—Treating the metal in the mould while it is molten or ductile ; Pressure or vacuum casting
    • B22D27/15—Treating the metal in the mould while it is molten or ductile ; Pressure or vacuum casting by using vacuum
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
    • B22D17/00—Pressure die casting or injection die casting, i.e. casting in which the metal is forced into a mould under high pressure
    • B22D17/14—Machines with evacuated die cavity
    • B22D17/145—Venting means therefor
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22C—FOUNDRY MOULDING
    • B22C9/00—Moulds or cores; Moulding processes
    • B22C9/02—Sand moulds or like moulds for shaped castings
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22C—FOUNDRY MOULDING
    • B22C9/00—Moulds or cores; Moulding processes
    • B22C9/08—Features with respect to supply of molten metal, e.g. ingates, circular gates, skim gates
    • B22C9/088—Feeder heads
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22C—FOUNDRY MOULDING
    • B22C9/00—Moulds or cores; Moulding processes
    • B22C9/10—Cores; Manufacture or installation of cores
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
    • B22D17/00—Pressure die casting or injection die casting, i.e. casting in which the metal is forced into a mould under high pressure
    • B22D17/20—Accessories: Details
    • B22D17/2015—Means for forcing the molten metal into the die
    • B22D17/2023—Nozzles or shot sleeves
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
    • B22D17/00—Pressure die casting or injection die casting, i.e. casting in which the metal is forced into a mould under high pressure
    • B22D17/20—Accessories: Details
    • B22D17/32—Controlling equipment
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
    • B22D18/00—Pressure casting; Vacuum casting
    • B22D18/06—Vacuum casting, i.e. making use of vacuum to fill the mould
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
    • B22D39/00—Equipment for supplying molten metal in rations
    • B22D39/06—Equipment for supplying molten metal in rations having means for controlling the amount of molten metal by controlling the pressure above the molten metal

Definitions

  • the present invention relates to a double casting method and apparatus. More specifically, the present invention may be applied to the mold with reduced pressure casting and gravity casting, to remove the pores and bubbles in the product to prevent casting defects and to solve the unformed problem can easily produce high heat-resistant cast steel products A casting method and apparatus.
  • the commonly used metal mold casting method is one of the most fundamental techniques of metal forming, and is used to manufacture large quantities of the same type of product.
  • the casting method is prepared by putting scrap, pig iron, ferroalloy, or nonferrous metal raw material into a furnace, heating and melting, pouring into a mold of sand or metal, cooling and solidifying. It is a principle that the molten metal is molded into a mold made of a desired model and then molded, and then the molten metal hardens to be the same metal object as the model. Casting can produce products in large quantities once the mold design is complete, but casting defects frequently involve undesired non-metallic components (inclusions) as part of the product in the final product. .
  • molten metal injected and dissolved in the atmosphere dissolves and absorbs a large amount of gases such as hydrogen, oxygen, and nitrogen. As the solubility decreases during coagulation, bubbles are generated, and some unresolved gases remain to prevent surface defects. It is also generated.
  • a method of casting using a vacuum technique is called a vacuum (decompression) casting method.
  • Such vacuum casting may be used in a manner in which melting is carried out in the air and then cast under vacuum conditions, or when the molten melt is received in a ladle in a ladle, and then vacuumed or cast in air.
  • the vacuum casting method When the vacuum casting method is used, harmful gas components can be easily removed, and the mechanical properties of the product are excellent, and thus the casting method is used to manufacture products such as stainless steel, heat resistant steel, tool steel, bearing steel, and magnetic materials.
  • this technique uses a vacuum pressure to inject molten metal into the mold to make the product.
  • insects Worm holes such as holes are created and some product surfaces have large amounts of non-fill casting defects.
  • the Republic of Korea Patent Publication No. 0477948 may cause a fatal problem of mold breakage with a low-strength sand mold because of the need to rapidly fill the molten metal with a ceramic cell mold using a vacuum pump, the cavity of the mold (cavity) Expensive ceramic cell molds when molten metal is rotated to 300 RPM to 600 RPM after the molten metal is filled, causing molten metal to break the mold or cause product fatal defects due to deformation. This is inevitably vulnerable at cost. Furthermore, such ceramic cell molds for precision casting are not applicable to products of internal insert shapes such as turbine housings because they do not collapse naturally after the molten metal is solidified.
  • the ceramic cell mold is used by heating to 900 °C or more.
  • the high temperature of the mold requires a long time of 600 seconds or more to solidify the molten metal, and has a fatal weakness in productivity. If the mold moves earlier, molten metal, not only solidified in the upright riser of heading 0947948, but also to the product connected to the gate, can escape into the source and cause fatal quality problems.
  • the company attempts to improve productivity by filling molten metal in the mold cavity and rotating it by centrifugal force until the product is completely solidified. However, the product still requires a long time of 300 seconds or more until it is completely solidified.
  • the injection tube was used once, and since the injection tube was made of the same material as the ceramic shell mold and connected together, there was a disadvantage that the molten metal was not separated even if it was solidified and thus could not be reused.
  • Hitchiner's anti-gravity vacuum casting technology has not been commercialized in the sand casting products, and other companies around the world have succeeded in the development of anti-gravity vacuum casting technology using suction pipes applied to the sand casting products. There is no mass production example.
  • the present inventors have repeatedly studied casting methods to overcome the above-mentioned problems and remove the sand molds and vacuum pressures instead of the ceramic precision casting molds, and double casting for recharging molten metal which has not been solidified by gravity by gravity.
  • the present invention was completed by producing a high temperature heat resistant stainless steel product by applying the technology.
  • Another object of the present invention to provide a duplex casting method that can easily remove the inclusions contained in the molten metal.
  • Still another object of the present invention is to provide a duplex casting method capable of producing a product having a high precision and a complicated shape.
  • Still another object of the present invention is to provide a duplex casting method which can have cost reduction and productivity increase effects.
  • Yet another object of the present invention is to provide a duplex casting apparatus.
  • the duplex casting device includes a casting chamber having a space portion therein; An injection tube mounted below the casting chamber and into which molten metal is injected; A mold that is detachably connected to the injection tube and has a cavity; A filling medium filled in the casting chamber and between the mold; And a pressure regulating means positioned on the casting chamber and depressurizing the inside of the casting chamber.
  • In one embodiment further comprises a riser for receiving the molten metal through the upper portion of the inside of the mold and discharged into the cavity.
  • the riser is formed from about 30% to about 120% by volume of the mold.
  • the melting furnace to form a melt by melting the raw material; characterized in that it further comprises.
  • the inner diameter of the injection tube is characterized in that larger than the inner diameter of the inlet of the cavity.
  • the ratio of the inner diameter of the cavity and the inner diameter of the injection tube is about 1: 1.1 to about 1: 3.
  • the pressure regulating means is characterized in that it comprises a suction screen, a vacuum pump and a suction pipe.
  • the double casting method includes depressurizing a casting chamber filled with a filling medium by pressure adjusting means to inject molten metal into a cavity inside a mold along an injection tube by a pressure difference from the outside; And releasing the depressurization of the casting chamber before the molten metal first injected into the cavity is solidified and secondaryly injected by gravity.
  • the melt injected into the riser is discharged by gravity to be injected into the cavity secondly do.
  • the method is characterized in that the mold is put into the injection chamber inside the injection tube is mounted and coupled to the injection tube, the injection chamber is filled with a filling medium, and the primary injection by decompression.
  • the injection speed of the molten metal injected into the mold is controlled by adjusting the speed of depressurizing the casting chamber.
  • the injection tube, the pressure adjusting means and the filling medium is characterized in that it is reused.
  • FIG. 1 shows a cross section of a duplex casting apparatus according to one embodiment of the invention.
  • Figure 2 (a) is a cross section of the injection tube according to an embodiment of the present invention
  • Figure 2 (b) shows a cross section of the injection tube according to another embodiment of the present invention.
  • FIG. 3 shows a duplex casting apparatus according to another embodiment of the invention.
  • One aspect of the invention relates to a duplex casting apparatus.
  • the duplex casting apparatus 100 includes a casting chamber 10 having a space formed therein; An injection tube 20 fixed to a lower portion of the casting chamber 10 and into which molten metal is injected; A mold 30 which is detachably connected to the injection tube 20 and has a cavity 35; A filling medium 40 filling between the casting chamber 10 and the mold 30; And pressure adjusting means (60) positioned on the casting chamber (10) and depressurizing the inside of the casting chamber (10).
  • the casting chamber 10 is filled with the filling medium 40 is formed in the space so as to fix the mold 30, the pressure control means 60 by the pressure control means 60 to reduce the mold ( 30) can be provided a reduced pressure atmosphere.
  • the injection tube 20 is inserted into the casting chamber 10 to be mounted and fixed at a lower portion thereof, and a part thereof may protrude to be immersed in the molten metal to inject the molten metal into the mold 30.
  • a plurality of injection tubes 10 may be installed.
  • the injection tube 20 may be made of a conventional material.
  • a fire resistant material such as ceramic may be used, which may prevent a reaction upon contact with the molten metal, but is not limited thereto.
  • an inner diameter d1 of the injection tube 20 may be larger than an inner diameter d2 of the cavity 35 in the present invention.
  • the residence time of the molten metal can be increased even when the pressure is released.
  • the ratio of the inner diameter d2 of the cavity 35 and the inner diameter d1 of the injection tube 20 (d2: d1) may be about 1: 1.1 to about 1: 3.
  • the residence time of the molten metal may be increased even when the pressurization of the casting chamber 10 is released in the above range.
  • the inlet shape of the injection tube 20 can be designed to be fitted to the mold.
  • Figure 2 (a) is a cross section of the injection tube 20 according to one embodiment of the present invention
  • Figure 2 (b) shows a cross section of the injection tube 21 according to another embodiment of the present invention.
  • the portion in contact with the bottom of the casting chamber may have a shape that is wider and narrower toward the top.
  • the mold 30 is detachably connected to the injection tube 20 and may have a cavity 35 in the form of a desired product.
  • the mold 30 may be made of a conventional material.
  • a sand mold may be used as the mold 30.
  • the mold 30 may include a sand, a water-soluble phenol resin, an ester curing agent, and the like, to obtain a mixed sand, and add the kneaded sand to a mold to prepare a mold, but is not limited thereto. .
  • the sand may be a conventional one.
  • silica sand, zircon sand, chromite sand, olivine sand or alumina sand may be used.
  • the sand may be used having a diameter of about 0.05mm to about 1mm.
  • a plurality of molds 30 may be installed in the casting chamber 10.
  • one to nine molds 30 may be installed to reduce costs and improve productivity through effective space allocation.
  • the resin attached to the sand disappears by heat, causing natural collapse. Therefore, since the mold 30 and the ceramic injection tube 20 are naturally separated, the injection tube 20 attached to the container can be reused to increase the cost reduction effect, and the injection tube 20 in the casting chamber 10 as shown in FIG. 1. ) Is fixed, and only the mold 30 can be continuously replaced, thereby increasing the productivity increase effect.
  • the filling medium 40 may be filled in the casting chamber 10 and around the mold 30 to support the mold 30.
  • the filling medium 40 may be used conventional.
  • refractory particles such as mixed sand or sand may be used, but are not limited thereto.
  • the filling medium 40 while filling the filling medium 40 while applying vibration to the casting chamber 10 for a predetermined time it can be filled uniformly while increasing the filling density.
  • the duplex casting apparatus 100 may further include a riser 50 that receives the molten metal through the upper part of the cavity 35 in the mold 30 and discharges it to the cavity by gravity.
  • the riser 50 may be included for the purpose of preventing casting defects such as bubbles or inclusions in the product during solidification of the mold 30.
  • the riser 50 may be located above the cavity 35 as in one embodiment of the present invention.
  • the lower surface of the riser 50 may be located above the upper surface of the cavity 35.
  • the bottom surface of riser 50 may have a spacing between the top surface of cavity 35 and about 1 cm to about 100 cm.
  • the initial unstable molten metal and remaining inclusions and impurities are moved upward to remove the product out of the product and the molten metal injected into the riser 50.
  • the gravity is injected into the lower cavity 30 from the riser 50 located at the upper side, and the air bubbles and air contained in the cavity 35 melt can be removed to prevent shrinkage defects and bubble defects of the product, easily prevent the inclusions included to prevent casting defects, it is possible to manufacture products of excellent precision and complex shape.
  • the riser 50 may be formed in a size of about 30% by volume to about 120% by volume of the mold 30. In embodiments it may be formed in a size of about 50% by volume to about 80% by volume.
  • Inclusions included in the molten metal in the above range can be easily removed, and bubbles and air remaining in the mold 30 can be easily removed.
  • the pressure adjusting means 60 may be positioned above the casting chamber 10 to reduce the pressure by adjusting the pressure inside the casting chamber 10.
  • the pressure adjusting means 60 may include a suction screen 64, a vacuum pump (not shown) and the suction pipe (62). Referring to FIG. 1, the suction screen 64 is connected to an upper portion of the casting chamber 10, and a suction pipe 62 is connected to one surface of the suction screen 64, and the suction pipe 62 is connected to a vacuum pump (not shown).
  • the pressure inside the casting chamber 10 can be adjusted by connecting and operating a vacuum pump.
  • the suction screen 64 may serve to pass only gas through the suction pipe 62 and prevent the suction of the filling medium 40 when the vacuum pump included in the pressure regulating means 60 operates.
  • the vacuum pump may adjust the pressure of the casting chamber 10 to control the gas removal and the molten metal injection rate inside the mold 30.
  • a conventional one can be used.
  • an ion pump and a diffusion pump may be used, but the present invention is not limited thereto.
  • the suction pipe 62 may reduce the pressure in the casting chamber 10 by discharging the gas inside the casting chamber 10 to the outside during the operation of the vacuum pump. At this time, it is possible to control the injection speed of the molten metal by adjusting the speed of reducing the pressure inside the casting chamber 10.
  • the duplex casting apparatus 100 may further include a melting furnace 70 for dissolving raw materials to form a molten metal.
  • the melting furnace 70 is positioned below the dual casting apparatus 100 such that the injection pipe 20 of the dual casting apparatus 100 is immersed in the molten metal inside the melting furnace 70, thereby casting
  • the molten metal can be injected by the reduced pressure of the chamber 10.
  • the injection tube 20 may be immersed in a melt formed in the melting furnace 70 to a depth of about 3 cm to about 10 cm. Under the above conditions, the injection rate of the molten metal can be easily adjusted while preventing the casting defect by preventing the external air from flowing into the molten metal to the maximum.
  • the melting furnace 70 may be a conventional one.
  • a molten metal may be formed by heating a received raw material using an electric furnace including a coil type heating element such as tungsten and kanthal.
  • the duplex casting method may include a step of firstly injecting the casting chamber 10 into the cavity 35 by decompressing the pressure, and releasing the second pressure to inject the secondly.
  • the casting chamber 10 filled with the filling medium 40 is depressurized by the pressure regulating means 60 so that the molten metal is injected along the injection pipe 20 by the pressure difference from the outside to the inside of the mold 30.
  • the double casting method is to put the mold 30 in the casting chamber 10, the injection tube 20 is mounted to combine with the injection tube 20, the inside of the casting chamber 10, the filling medium ( After filling with 40) it can be injected first by decompression through the pressure adjusting means.
  • duplex casting method will be described in detail step by step.
  • the step is to dissolve the raw material contained in the melting furnace 70 to form a molten metal.
  • An electric furnace may be used as the melting furnace 70, and the raw material may be dissolved by heating using a heating element coil included in the electric furnace, but is not limited thereto.
  • the step is filling the filling medium 40 between the casting chamber 10 and the mold 30, and then depressurizing the internal pressure of the casting chamber 10 through the pressure adjusting means (60). .
  • the reduced pressure may be adjusted to about 10 ⁇ 2 torr to about 10 ⁇ 5 torr. Under the above conditions, the injection speed of the molten metal can be easily adjusted, and casting defects can be prevented.
  • the injection tube 20 of the reduced pressure casting chamber 10 is immersed in the manufactured molten metal, and the molten metal is poured along the injection tube 20 by the pressure difference between the casting chamber 10 and the outside. ) Is first injected into the cavity 35 inside.
  • the injection tube 20 is infiltrated into the molten metal formed in the melting furnace 70 to a depth of about 3cm to about 10cm may be injected into the molten metal.
  • the injection speed of the molten metal can be easily adjusted while preventing the casting defect by preventing the external air from flowing into the molten metal as much as possible.
  • the injection speed of the molten metal injected into the mold 30 may be adjusted by adjusting the decompression speed of the casting chamber 10 during the decompression. Specifically, the injection of the molten metal by adjusting the depressurization rate applied through the pressure adjusting means 60 to minimize turbulence according to the shape of the desired product through the data obtained through the manufacture of repeated products You can adjust the speed.
  • the decompression rate can be adjusted from about 0.1 cm / s to about 30 cm / s.
  • bubbles are generated by turbulence of the molten metal when the injection rate is adjusted, thereby preventing casting defects such as unmolding by hindering the filling of the molten metal in the mold 30.
  • the injection speed of the molten metal injected into the riser 50 formed through the upper part of the cavity 35 may be adjusted by adjusting the decompression speed of the casting chamber 10 during the decompression.
  • the decompression of the casting chamber 10 is released, and the second injection is performed by gravity.
  • the primary injection is where the melt moves from bottom to top, while the secondary injection moves from top to bottom.
  • the molten metal first injected into the cavity 35 starts directional solidification from the outside of the cavity 35. Therefore, the relatively low density inclusions (or impurities) may be easily solidified on the surface of the cavity 35. In addition, pores and bubbles formed in the cavity 35 may be easily removed while the second injection.
  • the molten metal injected into the riser 50 is discharged by gravity when the pressure is released from the casting chamber 10. Secondary injection into the cavity 35 can be made. As the molten metal injected up to the riser 50 is secondly injected into the mold 30 by gravity, pores and bubbles formed in the cavity 35 may be easily removed.
  • the step is to disassemble the second injection chamber 10 to obtain a product formed inside the mold (30).
  • FIG. 3 shows a duplex casting apparatus 100 according to another embodiment of the invention.
  • the injection tube 20, the pressure regulator 60, and the filling medium 40 may be easily detached from the casting chamber 10a.
  • the casting chamber 10a is separated and dismantled, and the injection tube 20, the pressure regulator 60, and the filling medium 40 are removed. Is mounted on the other casting chamber (10b) can be reused can have a cost reduction effect.
  • a lower portion of the cylindrical injection chamber 10 having a diameter of 600 mm and a height of 800 mm has a shape as shown in FIG. 2 (a) and a 200 mm long ceramic injection tube 20 is installed.
  • a mold 30 having a cavity 35 was prepared by using a kneaded sand made of alumina sand, a water-soluble phenolic resin, and an ester curing agent, and formed at the inlet of the injection tube 20. Overlay was placed inside the injection chamber (10). At this time, the injection pipe inner diameter (d1) is ⁇ 50mm, the cavity inlet diameter (d2) was used to form a size of ⁇ 25mm.
  • the mold 30 was equipped with a riser 50 communicating with the upper portion of the cavity 35. At this time, the riser 50 was formed to have a size of 65% by volume with respect to the entire volume of the mold 30.
  • the formed mold 30 as shown in FIG. 1 was overlaid on the injection tube 20 so as not to generate a gap.
  • the filling chamber 40 was charged while vibrating between the injection chamber 10 and the mold 30 with a filling medium 40.
  • a raw material is added and heated to prepare a molten metal, and then a suction screen 60, a suction pipe 62, and an upper portion of the injection chamber 10.
  • the pressure adjusting means 60 including a vacuum pump (not shown) to operate a vacuum pump (not shown) to maintain the interior of the injection chamber 10 in a vacuum state of 10 -3 torr.
  • the ceramic injection tube 20 is immersed in the molten metal produced in the electric furnace to a depth of 50 mm to first inject the molten metal into the injection tube 20 to the mold 30 and the riser 50. The molten metal was injected.
  • the vacuum pump was turned off so that the molten metal injected up to the riser 50 by gravity was injected into the cavity 35 by gravity before the first molten molten metal solidified.
  • the injection chamber 10 was moved and placed on a disassembly conveyor to obtain a product formed in the cavity 35 in the mold 30. At this time, the obtained product did not cause casting defects such as bubbles, wormholes and unmolded.

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  • Mechanical Engineering (AREA)
  • Molds, Cores, And Manufacturing Methods Thereof (AREA)
  • Casting Support Devices, Ladles, And Melt Control Thereby (AREA)

Abstract

The present invention relates to a double casting apparatus and a double casting method. The double casting apparatus comprises: a casting chamber having a space formed therein; an injection pipe provided at the lower portion of the casting chamber and injecting molten metal; a mold detachably connected to the injection pipe and having a cavity; a filling medium to be filled between the inside of the casting chamber and the mold; and a pressure control means placed at the upper portion of the casting chamber and reducing the internal pressure of the casting chamber.

Description

이중 주조 방법 및 장치Duplex casting method and apparatus
본 발명은 이중 주조 방법 및 장치에 관한 것이다. 보다 구체적으로 본 발명은 주형에 감압주조 및 중력주조를 함께 적용하여, 제품 내 기공 및 기포를 제거하여 주조결함을 방지할 수 있고 미성형 문제를 해결하여 고내열주강 제품을 용이하게 생산할 수 있는 이중 주조 방법 및 장치에 관한 것이다.The present invention relates to a double casting method and apparatus. More specifically, the present invention may be applied to the mold with reduced pressure casting and gravity casting, to remove the pores and bubbles in the product to prevent casting defects and to solve the unformed problem can easily produce high heat-resistant cast steel products A casting method and apparatus.
일반적으로 이용되는 금속 주조(metal mold casting)법은 금속 조형의 가장 근본적인 기법중 하나로 같은 형태의 제품을 대량으로 제조하기 위해 사용된다. 주조 방식은 로(furnace) 안에 스크랩, 선철, 합금철 또는 비철금속 원료를 넣고 가열 및 용해한 다음, 모래나 금속재의 거푸집(mold) 속에 부어 넣고 냉각 및 응고시켜 제조한다. 원하는 형태의 모형으로 제조된 거푸집에 용융 금속을 주입해 성형시킨 뒤 용융금속이 굳으면 모형과 동일한 금속물체가 되는 원리이다. 주조는 주형 설계가 완료되면 대량으로 제품을 생산할 수 있으나, 주물의 응고 과정에서 제품 원료로서 원치 않는, 금속물질이 아닌 비금속 성분(개재물, inclusion)이 최종 제품에 개재되는 주조결함이 빈번하게 발생한다. 또한 대기 중에서 용해되어 주입된 용탕은 상당량의 수소, 산소 및 질소 등의 가스를 용해 및 흡수하고 있어, 응고시 용해도가 감소하면서 기포가 발생하게 되며, 미처 방출되지 못한 일부 가스는 잔존하여 표면 결함을 발생시키기도 한다.The commonly used metal mold casting method is one of the most fundamental techniques of metal forming, and is used to manufacture large quantities of the same type of product. The casting method is prepared by putting scrap, pig iron, ferroalloy, or nonferrous metal raw material into a furnace, heating and melting, pouring into a mold of sand or metal, cooling and solidifying. It is a principle that the molten metal is molded into a mold made of a desired model and then molded, and then the molten metal hardens to be the same metal object as the model. Casting can produce products in large quantities once the mold design is complete, but casting defects frequently involve undesired non-metallic components (inclusions) as part of the product in the final product. . In addition, molten metal injected and dissolved in the atmosphere dissolves and absorbs a large amount of gases such as hydrogen, oxygen, and nitrogen. As the solubility decreases during coagulation, bubbles are generated, and some unresolved gases remain to prevent surface defects. It is also generated.
이러한 결함을 방지하기 위하여 진공기술을 이용하여 주조하는 방법을 진공(감압) 주조법이라 한다. 이러한 진공 주조는 용해를 대기중에서 실시한 다음 진공조건 하에서 주조하거나, 대기 중에서 용해된 용탕을 래들에 받을 때 진공상태로 처리한 다음 진공 또는 대기 중에서 주조하는 방식 등으로 이용될 수 있다. In order to prevent such defects, a method of casting using a vacuum technique is called a vacuum (decompression) casting method. Such vacuum casting may be used in a manner in which melting is carried out in the air and then cast under vacuum conditions, or when the molten melt is received in a ladle in a ladle, and then vacuumed or cast in air.
이러한 진공 주조법을 사용시 유해가스 성분을 용이하게 제거할 수 있으며, 제품의 기계적 성질이 우수하게 되어 스테인레스강, 내열강, 공구강, 베어링강 및 자성재료 등의 제품제조에 사용되는 주조법이다. When the vacuum casting method is used, harmful gas components can be easily removed, and the mechanical properties of the product are excellent, and thus the casting method is used to manufacture products such as stainless steel, heat resistant steel, tool steel, bearing steel, and magnetic materials.
이러한 진공 주조법의 한 종류인 반중력 진공주조(countergravity vacuum assisted casting)법은, 미국 Hitchiner사 등에서 1970~1980년대에 개발된 것으로, 이는 세라믹(ceramic)관을 용탕(molten metal) 속에 잠입하여 진공장치(Vacuum System)를 통해 용탕을 주형내로 빠르게 흡입하는 방식이다. 대표적인 반중력 진공주조 및 진공주조 장치와 관련한 특허로는 대한민국 등록특허공보 제0947948호 및 제0801815호가 있다. 그러나 상기 등록특허에 기재된 Hitchiner사의 주조 방식은 세라믹 몰드에 의한 정밀주조 제품 생산에 국한되어 있어 특히, 사형(沙型, Sand Mold)주조 방식의 제품 생산에는 용탕의 빠른 흡입 시 사형이 견디어 내지 못하여 개재물 혼입 등의 주조결함이 다량 발생하는 등 심각한 문제점을 가지고 있다. 또한, 이 기술은 진공압력(vacuum pressure)만을 이용하여 주형 내로 용탕(molten metal)을 흡입하여 제품을 만드는 방식으로서 급격한 용탕의 흐름으로 인해 제품 내부에 작은 기포(porosity)뿐만 아니라 경우에 따라서는 벌레구멍과 같은 큰 홀(worm hole)이 생기고 일부 제품 표면에는 미성형(未成型, non fill) 주조 결함을 다량 갖고 있다.Countergravity vacuum assisted casting, one of the vacuum casting methods, was developed in the 1970s and 1980s by Hitchiner, Inc. in the United States, which infiltrates a ceramic tube into a molten metal and vacuums it. (Vacuum System) quickly inhales the molten metal into the mold. Patents related to representative antigravity vacuum casting and vacuum casting apparatus are Korean Patent Nos. 0477948 and 0080518. However, Hitchiner's casting method described in the registered patent is limited to the production of precision casting products by ceramic mold, and in particular, the production of sand mold casting methods does not withstand the death of molds due to rapid suction of molten metal. It has serious problems such as a large amount of casting defects such as mixing. In addition, this technique uses a vacuum pressure to inject molten metal into the mold to make the product. In addition to the small porosity inside the product due to the rapid flow of the melt, in some cases, insects Worm holes such as holes are created and some product surfaces have large amounts of non-fill casting defects.
특히, 대한민국 등록특허공보 제0947948호에서는 진공펌프를 이용하여 용융금속을 세라믹 셀 주형으로 급속히 채워야하는 이유로 강도가 낮은 사형주형으로는 형 파손의 치명적인 문제점이 발생될 수 있고, 주형의 공동(cavity)에 용융금속을 채운 후 용기를 300 RPM 내지 600 RPM으로 회전할시, 용융금속이 주형을 파손하거나 변형으로 인해 제품 치수의 변화를 초래하여 품질의 치명적인 결함을 야기할 수 있기 때문에 고가의 세라믹 셀주형이 사용될 수밖에 없어 원가적으로 취약하다. 더 나아가 이러한 정밀주조용 세라믹 셀 주형은 용융금속이 고형화된 후 자연 붕괴가 되지 않기 때문에 터빈하우징 등의 내부 인서트 형상의 제품에는 적용이 불가하다.In particular, the Republic of Korea Patent Publication No. 0477948 may cause a fatal problem of mold breakage with a low-strength sand mold because of the need to rapidly fill the molten metal with a ceramic cell mold using a vacuum pump, the cavity of the mold (cavity) Expensive ceramic cell molds when molten metal is rotated to 300 RPM to 600 RPM after the molten metal is filled, causing molten metal to break the mold or cause product fatal defects due to deformation. This is inevitably vulnerable at cost. Furthermore, such ceramic cell molds for precision casting are not applicable to products of internal insert shapes such as turbine housings because they do not collapse naturally after the molten metal is solidified.
또한, 상기 세라믹 셀 주형은 900℃ 이상으로 가열하여 사용한다. 이때, 주형의 높은 온도로 인해 용융금속이 응고되기 까지는 600초 이상의 장시간을 요하게 되어, 생산성에 치명적인 약점을 갖고 있다. 만약 이보다 빠른 시간에 주형을 움직이면 제0947948호의 직립 라이저내 용융금속 뿐만 아니라 게이트에 연결된 제품까지 미처 응고되지 않는 용융금속이 소스로 빠져 나와 치명적인 품질문제를 야기할 수 있다. 이에 개선방안으로 용융금속을 주형공동에 채운 후 제품이 완전히 고형화 되기까지 원심력으로 회전을 하여 생산성을 개선하려고 시도하고 있다. 하지만 제품이 완전히 고형화 되기까지는 여전히 300초 이상의 장시간이 요구되는 문제점을 갖고 있다.In addition, the ceramic cell mold is used by heating to 900 ℃ or more. At this time, the high temperature of the mold requires a long time of 600 seconds or more to solidify the molten metal, and has a fatal weakness in productivity. If the mold moves earlier, molten metal, not only solidified in the upright riser of heading 0947948, but also to the product connected to the gate, can escape into the source and cause fatal quality problems. As a measure of improvement, the company attempts to improve productivity by filling molten metal in the mold cavity and rotating it by centrifugal force until the product is completely solidified. However, the product still requires a long time of 300 seconds or more until it is completely solidified.
또한, 상기 대한민국 등록특허공보 제0947948호는 용기를 회전하므로 제품 주형을 좌우 대칭이 되는 정방향으로 배치해야 효과적이므로 제품의 형상에 제한이 따른다. 또한, 세라믹 셀주형을 용기의 중앙부에 위치해야 원심력을 제품 모두에 일정하게 가할 수 있으므로 여러 주형공동이 방사형으로 부착된 단일 세라믹 셀주형을 사용한다.In addition, the Republic of Korea Patent Publication No. 0477948, because the rotation of the container is effective to place the product mold in the positive direction to be symmetrical, so the shape of the product is limited. In addition, since the ceramic cell mold must be placed at the center of the container, the centrifugal force can be uniformly applied to all products. Therefore, a single ceramic cell mold with multiple mold cavities radially attached is used.
또한, 이러한 정밀주조용 주형에서는 주입관을 1회 소모성으로 사용하였고, 주입관이 세라믹 쉘 주형과 동일한 재질로 제작되어 함께 연결되기 때문에 용융금속이 고형화가 되어도 분리되지 않아 재사용이 불가능한 단점이 있었다.In addition, in such a precision casting mold, the injection tube was used once, and since the injection tube was made of the same material as the ceramic shell mold and connected together, there was a disadvantage that the molten metal was not separated even if it was solidified and thus could not be reused.
이러한 문제점으로 인해 Hitchiner사의 반중력 진공주조 기술은 사형주조의 제품에는 상용화가 이루어지지 않고 있을 뿐만 아니라 전세계 여느 업체에서도 아직까지 사형주조의 제품에 적용되는 흡입관을 이용한 반중력 진공주조 기술 개발이 성공하여 양산화된 예가 전무한 실정이다.Due to these problems, Hitchiner's anti-gravity vacuum casting technology has not been commercialized in the sand casting products, and other companies around the world have succeeded in the development of anti-gravity vacuum casting technology using suction pipes applied to the sand casting products. There is no mass production example.
이에 본 발명자는 상기한 문제점을 극복하기 위한 주조방안 연구를 거듭하여 세라믹 정밀주조 주형이 아닌 사형주형과 진공압을 제거함으로써 흡입되어 아직 응고되지 않은 용탕을 중력에 의해 재충전하는 이중주조(Duplex Casting)기술을 적용하여 고온 내열강 스테인레스 스틸(Stainless Steel) 제품을 생산하여 본 발명을 완성하였다.Accordingly, the present inventors have repeatedly studied casting methods to overcome the above-mentioned problems and remove the sand molds and vacuum pressures instead of the ceramic precision casting molds, and double casting for recharging molten metal which has not been solidified by gravity by gravity. The present invention was completed by producing a high temperature heat resistant stainless steel product by applying the technology.
본 발명의 목적은 제품 주조시 수축결함, 기포결함 및 기타 주조결함을 방지할 수 있는 이중 주조방법을 제공하는 것이다.It is an object of the present invention to provide a duplex casting method which can prevent shrinkage defects, bubble defects and other casting defects during product casting.
본 발명의 다른 목적은 용탕 내 포함되는 개재물을 용이하게 제거할 수 있는 이중 주조방법을 제공하는 것이다.Another object of the present invention to provide a duplex casting method that can easily remove the inclusions contained in the molten metal.
본 발명의 또 다른 목적은 정밀도가 우수하고, 복잡한 형상의 제품제조가 가능한 이중 주조방법을 제공하는 것이다.Still another object of the present invention is to provide a duplex casting method capable of producing a product having a high precision and a complicated shape.
본 발명의 또 다른 목적은 원가절감 및 생산성 증대 효과를 가질 수 있는 이중 주조방법을 제공하는 것이다.Still another object of the present invention is to provide a duplex casting method which can have cost reduction and productivity increase effects.
본 발명의 또 다른 목적은 이중 주조장치를 제공하는 것이다.Yet another object of the present invention is to provide a duplex casting apparatus.
본 발명의 하나의 관점은 이중 주조 장치에 관한 것이다. 상기 이중 주조 장치는 내부에 공간부가 형성된 주조챔버; 상기 주조챔버 하부에 장착되며, 용탕이 주입되는 주입관; 상기 주입관과 탈부착 가능하도록 연결되며, 캐비티(cavity)를 가지는 주형; 상기 주조챔버 내부 및 상기 주형 사이에 충진되는 충진매체; 및 상기 주조챔버 상부에 위치하며 상기 주조챔버 내부를 감압하는 압력조절수단;을 포함하여 구성되는 것을 특징으로 한다.One aspect of the invention relates to a duplex casting apparatus. The duplex casting device includes a casting chamber having a space portion therein; An injection tube mounted below the casting chamber and into which molten metal is injected; A mold that is detachably connected to the injection tube and has a cavity; A filling medium filled in the casting chamber and between the mold; And a pressure regulating means positioned on the casting chamber and depressurizing the inside of the casting chamber.
한 구체예에서 상기 주형 내부의 캐비티 상부와 통하여 용탕을 수용하고 캐비티로 배출하는 라이저;를 더 포함하는 것을 특징으로 한다.In one embodiment further comprises a riser for receiving the molten metal through the upper portion of the inside of the mold and discharged into the cavity.
한 구체예에서 상기 라이저는 상기 주형의 약 30 부피% 내지 약 120 부피% 크기로 형성되는 것을 특징으로 한다.In one embodiment the riser is formed from about 30% to about 120% by volume of the mold.
한 구체예에서 원료를 용해하여 용탕을 형성시키는 용해로;를 더 포함하는 것을 특징으로 한다.In one embodiment, the melting furnace to form a melt by melting the raw material; characterized in that it further comprises.
한 구체예에서 상기 주입관의 내경은 캐비티의 입구 내경보다 큰 것을 특징으로 한다.In one embodiment the inner diameter of the injection tube is characterized in that larger than the inner diameter of the inlet of the cavity.
한 구체예에서 상기 캐비티의 내경과 상기 주입관의 내경의 비는 약 1:1.1~약 1:3인 것을 특징으로 한다.In one embodiment, the ratio of the inner diameter of the cavity and the inner diameter of the injection tube is about 1: 1.1 to about 1: 3.
한 구체예에서 상기 압력조절수단은 흡입 스크린, 진공펌프 및 흡입관을 포함하는 것을 특징으로 한다.In one embodiment the pressure regulating means is characterized in that it comprises a suction screen, a vacuum pump and a suction pipe.
본 발명의 다른 관점은 상기 이중 주조 장치를 이용한 이중 주조 방법에 관한 것이다. 상기 이중 주조 방법은 충진매체가 충진된 주조챔버를 압력조절수단에 의해 감압하여 외부와의 압력차에 의해 용탕을 주입관을 따라 주형 내부의 캐비티에 1차 주입하고; 그리고 상기 캐비티에 1차 주입된 용탕이 응고되기 전에 상기 주조챔버의 감압을 해제하여, 중력에 의해 2차 주입되는 단계;를 포함하는 것을 특징으로 한다.Another aspect of the invention relates to a duplex casting method using the duplex casting apparatus. The double casting method includes depressurizing a casting chamber filled with a filling medium by pressure adjusting means to inject molten metal into a cavity inside a mold along an injection tube by a pressure difference from the outside; And releasing the depressurization of the casting chamber before the molten metal first injected into the cavity is solidified and secondaryly injected by gravity.
한 구체예에서 상기 1차 주입시, 주형 내부의 캐비티 상부와 통하여 형성된 라이저에도 주입되고, 주조챔버의 감압 해제시 상기 라이저에 주입된 용탕이 중력에 의해 배출되어 캐비티에 2차 주입되는 것을 특징으로 한다.In one embodiment, during the first injection, it is also injected into the riser formed through the upper cavity inside the mold, and when the decompression of the casting chamber is released, the melt injected into the riser is discharged by gravity to be injected into the cavity secondly do.
한 구체예에서 상기 방법은 주입관이 장착된 주조챔버 내부에 주형을 넣어 주입관과 결합시키고, 상기 주조챔버 내부를 충진매체로 채운 후 감압에 의해 1차 주입하는 것을 특징으로 한다.In one embodiment, the method is characterized in that the mold is put into the injection chamber inside the injection tube is mounted and coupled to the injection tube, the injection chamber is filled with a filling medium, and the primary injection by decompression.
한 구체예에서 상기 주조챔버를 감압하는 속도를 조절하여 상기 주형에 주입되는 용탕의 주입속도를 조절하는 것을 특징으로 한다.In an embodiment, the injection speed of the molten metal injected into the mold is controlled by adjusting the speed of depressurizing the casting chamber.
상기 주입관, 압력조절수단 및 상기 충진매체는 재사용되는 것을 특징으로 한다.The injection tube, the pressure adjusting means and the filling medium is characterized in that it is reused.
본 발명의 이중 주조 방법 및 장치를 적용시 제품의 수축결함 및 기포결함을 방지할 수 있고, 용탕 내 포함되는 개재물을 용이하게 제거하여 주조결함을 방지할 수 있고, 정밀도가 우수하고, 복잡한 형상의 제품제조가 가능하며, 주입구, 압력조절장치 및 충진매체 등의 재사용이 가능하여 원가절감 및 생산성 증대 효과를 가질 수 있다.When applying the dual casting method and apparatus of the present invention, it is possible to prevent shrinkage defects and bubble defects of the product, to easily remove the inclusions in the molten metal to prevent casting defects, excellent precision, complex shape It is possible to manufacture the product, and it is possible to reuse the inlet, the pressure regulating device and the filling medium, thereby reducing the cost and increasing the productivity.
도 1은 본 발명의 한 구체예에 따른 이중 주조 장치의 단면을 나타낸다.1 shows a cross section of a duplex casting apparatus according to one embodiment of the invention.
도 2 (a)는 본 발명의 한 구체예에 따른 주입관의 단면이며, 도 2 (b)는 본 발명의 다른 구체예에 따른 주입관의 단면을 나타낸다.Figure 2 (a) is a cross section of the injection tube according to an embodiment of the present invention, Figure 2 (b) shows a cross section of the injection tube according to another embodiment of the present invention.
도 3은 본 발명의 다른 구체예에 따른 이중 주조 장치를 나타낸다. 3 shows a duplex casting apparatus according to another embodiment of the invention.
본 발명의 하나의 관점은 이중 주조 장치에 관한 것이다. One aspect of the invention relates to a duplex casting apparatus.
도 1은 본 발명의 한 구체예에 따른 이중 주조 장치의 단면을 나타낸다. 도 1을 참조하면, 상기 이중 주조 장치(100)는 내부에 공간부가 형성된 주조챔버(10); 상기 주조챔버(10) 하부에 고정되며, 용탕이 주입되는 주입관(20); 상기 주입관(20)과 탈부착 가능하도록 연결되며, 캐비티(cavity)(35)를 가지는 주형(30); 상기 주조챔버(10) 내부 및 상기 주형(30) 사이에 충진되는 충진매체(40); 및 상기 주조챔버(10) 상부에 위치하며 상기 주조챔버(10) 내부를 감압하는 압력조절수단(60);을 포함하여 구성되는 것을 특징으로 한다.1 shows a cross section of a duplex casting apparatus according to one embodiment of the invention. Referring to FIG. 1, the duplex casting apparatus 100 includes a casting chamber 10 having a space formed therein; An injection tube 20 fixed to a lower portion of the casting chamber 10 and into which molten metal is injected; A mold 30 which is detachably connected to the injection tube 20 and has a cavity 35; A filling medium 40 filling between the casting chamber 10 and the mold 30; And pressure adjusting means (60) positioned on the casting chamber (10) and depressurizing the inside of the casting chamber (10).
상기 주조챔버(10) 내부에는 상기 충진매체(40)가 충진되어 상기 주형(30)을 고정시킬 수 있도록 공간부가 형성되어 있고, 상기 압력조절수단(60)에 의해 대기압이하로 감압하여 상기 주형(30)에 감압된 분위기를 제공할 수 있다.The casting chamber 10 is filled with the filling medium 40 is formed in the space so as to fix the mold 30, the pressure control means 60 by the pressure control means 60 to reduce the mold ( 30) can be provided a reduced pressure atmosphere.
상기 주입관(20)은 상기 주조챔버(10) 내부에 삽입되어 하부에 장착되어 고정되며, 일부는 돌출되어 용탕 내부에 침지되어 상기 용탕을 상기 주형(30)에 주입시킬 수 있다. 도면에는 주입관(20)이 하나인 것만 도시하였으나, 다른 구체예에서는 주조챔버(10)에 복수개로도 설치될 수 있다. The injection tube 20 is inserted into the casting chamber 10 to be mounted and fixed at a lower portion thereof, and a part thereof may protrude to be immersed in the molten metal to inject the molten metal into the mold 30. Although only one injection tube 20 is illustrated in the drawing, in another embodiment, a plurality of injection tubes 10 may be installed.
상기 주입관(20)은 통상적인 재질로 이루어진 것을 사용할 수 있다. 예를 들면, 상기 용탕과 접촉시 반응을 방지할 수 있는 세라믹(ceramic)과 같은 내화성 재질을 사용할 수 있으나, 이에 제한되지 않는다.The injection tube 20 may be made of a conventional material. For example, a fire resistant material such as ceramic may be used, which may prevent a reaction upon contact with the molten metal, but is not limited thereto.
상기 도 1을 참조하면, 본 발명에서 상기 주입관(20)의 내경(d1)은 상기 캐비티(35)의 내경(d2)보다 클 수 있다. 이 경우 감압 해제 시에도 용탕의 체류 시간을 증가시킬 수 있다. 한 구체예에서는 상기 캐비티(35)의 내경(d2) 및 상기 주입관(20)의 내경(d1) 비(d2:d1)는 약 1:1.1~약 1:3 일 수 있다. 바람직하게는 약 1:1.5~약 1:2.5 일 수 있다. 더욱 바람직하게는 약 1:2 일 수 있다. 상기 범위에서 상기 주조챔버(10)의 가압을 해제할 시에도 상기 용탕의 체류시간을 증가시킬 수 있다.Referring to FIG. 1, an inner diameter d1 of the injection tube 20 may be larger than an inner diameter d2 of the cavity 35 in the present invention. In this case, the residence time of the molten metal can be increased even when the pressure is released. In one embodiment, the ratio of the inner diameter d2 of the cavity 35 and the inner diameter d1 of the injection tube 20 (d2: d1) may be about 1: 1.1 to about 1: 3. Preferably about 1: 1.5 to about 1: 2.5. More preferably about 1: 2. The residence time of the molten metal may be increased even when the pressurization of the casting chamber 10 is released in the above range.
상기 주입관(20)의 입구 형태는 주형에 끼워질 수 있도록 설계할 수 있다. 도 2 (a)는 본 발명의 한 구체예에 따른 주입관(20)의 단면이며, 도 2 (b)는 본 발명의 다른 구체예에 따른 주입관(21)의 단면을 나타낸다. 도 2 (a) 및 도 2 (b)에 도시된 바와 같이, 주조챔버 바닥면에 접하는 부분은 넓게 하고 상부로 갈수록 좁아지는 형태를 가질 수 있다.  The inlet shape of the injection tube 20 can be designed to be fitted to the mold. Figure 2 (a) is a cross section of the injection tube 20 according to one embodiment of the present invention, Figure 2 (b) shows a cross section of the injection tube 21 according to another embodiment of the present invention. As shown in Figure 2 (a) and 2 (b), the portion in contact with the bottom of the casting chamber may have a shape that is wider and narrower toward the top.
상기 주형(mold)(30)은 상기 주입관(20)과 탈부착 가능하게 연결되며, 원하는 제품 형태의 캐비티(cavity)(35)를 가질 수 있다.The mold 30 is detachably connected to the injection tube 20 and may have a cavity 35 in the form of a desired product.
상기 주형(30)은 통상적인 재질로 이루어진 것을 사용할 수 있다. 예를 들면, 상기 주형(30)으로 사형주형을 사용할 수 있다. 구체예에서 주형(30)은 모래, 수용성 페놀 수지 및 에스테르계 경화제 등을 포함하여 혼련사(mixed sand)를 얻고, 상기 혼련사를 틀에 투입하여 주형을 제조하여 사용할 수 있으나, 이에 제한되지 않는다.The mold 30 may be made of a conventional material. For example, a sand mold may be used as the mold 30. In an embodiment, the mold 30 may include a sand, a water-soluble phenol resin, an ester curing agent, and the like, to obtain a mixed sand, and add the kneaded sand to a mold to prepare a mold, but is not limited thereto. .
상기 모래는 통상적인 것을 사용할 수 있다. 예를 들면, 규사, 지르콘사, 크로마이트사(chromite sand), 올리빈사(olivine sand) 또는 알루미나 모래를 사용할 수 있다. 구체예에서 상기 모래는 직경이 약 0.05mm 내지 약 1mm인 것을 사용할 수 있다. The sand may be a conventional one. For example, silica sand, zircon sand, chromite sand, olivine sand or alumina sand may be used. In embodiments, the sand may be used having a diameter of about 0.05mm to about 1mm.
본 발명의 구체예에서 주조챔버(10) 내부에는 복수 개의 주형(30)이 설치될 수 있다. 예를 들면, 1 개 내지 9 개의 주형(30)이 설치되어, 효과적인 공간 할용을 통해 원가 절감 및 생산성을 향상시킬 수 있다.In the exemplary embodiment of the present invention, a plurality of molds 30 may be installed in the casting chamber 10. For example, one to nine molds 30 may be installed to reduce costs and improve productivity through effective space allocation.
사형주형은 일정시간이 지난 후에 모래 주위에 부착된 레진이 열에 의해 소멸되어 자연붕괴가 일어난다. 따라서 주형(30)과 세라믹 주입관(20)이 자연분리되므로 용기에 부착된 주입관(20)은 재사용이 가능하여 원가절감효과를 높이고, 도 1과 같이 주조챔버(10)에 주입관(20)은 고정되고, 주형(30)만 계속해서 교체할 수 있어 생산성 증대효과를 높일 수 있다. In the mold, after a certain time, the resin attached to the sand disappears by heat, causing natural collapse. Therefore, since the mold 30 and the ceramic injection tube 20 are naturally separated, the injection tube 20 attached to the container can be reused to increase the cost reduction effect, and the injection tube 20 in the casting chamber 10 as shown in FIG. 1. ) Is fixed, and only the mold 30 can be continuously replaced, thereby increasing the productivity increase effect.
상기 충진매체(40)는 상기 주조챔버(10) 내부와 상기 주형(30) 주위에 충진되어 상기 주형을(30) 지지할 수 있다. 상기 충진매체(40)는 통상적인 것을 사용할 수 있다. 예를 들면, 혼련사(mixed sand) 또는 모래 등의 내화성 입자를 사용할 수 있으나, 이에 제한되지 않는다.The filling medium 40 may be filled in the casting chamber 10 and around the mold 30 to support the mold 30. The filling medium 40 may be used conventional. For example, refractory particles such as mixed sand or sand may be used, but are not limited thereto.
한 구체예에서는 일정시간 동안 상기 주조챔버(10)에 진동을 가하면서 상기 충진매체(40)를 충진하여 충진 밀도를 증가시키면서 균일하게 충진할 수 있다.In one embodiment, while filling the filling medium 40 while applying vibration to the casting chamber 10 for a predetermined time it can be filled uniformly while increasing the filling density.
한 구체예에서 상기 이중 주조 장치(100)는 상기 주형(30) 내부의 캐비티(35) 상부와 통하여 용탕을 수용하고 중력에 의해 캐비티로 배출하는 라이저(50)를 더 포함할 수 있다. 상기 라이저(50)는 상기 주형(30)의 응고시 개재물이 제품에 포함되거나 기포 등의 주조결함을 방지하는 목적으로 포함될 수 있다. 도 1을 참조하면, 본 발명의 한 구체예에서 같이 상기 라이저(50)는 상기 캐비티(35)의 상부에 위치될 수 있다. 구체예에서는 라이저(50)의 하부면은 캐비티(35)의 상부면 보다 위에 위치할 수 있다. 구체예에서 라이저(50)의 하부면은 캐비티(35)의 상부면의 간격은 약 1 cm 내지 약 100 cm 일 수 있다.In one embodiment, the duplex casting apparatus 100 may further include a riser 50 that receives the molten metal through the upper part of the cavity 35 in the mold 30 and discharges it to the cavity by gravity. The riser 50 may be included for the purpose of preventing casting defects such as bubbles or inclusions in the product during solidification of the mold 30. Referring to FIG. 1, the riser 50 may be located above the cavity 35 as in one embodiment of the present invention. In an embodiment the lower surface of the riser 50 may be located above the upper surface of the cavity 35. In embodiments, the bottom surface of riser 50 may have a spacing between the top surface of cavity 35 and about 1 cm to about 100 cm.
따라서 용탕이 주형(30) 하부부터 충진되어 상부에 위치한 라이저(50)로 이동시 초기 불안정한 용탕과 잔존하고 있는 개재물 및 불순물을 상부로 이동하여 제품 밖으로 제거하는 기능과, 라이저(50)에 주입된 용탕이 중력에 의해 상부에 위치한 라이저(50)에서 하부의 캐비티(30)로 주입되어, 캐비티(35) 용탕에 포함된 기포 및 공기를 제거할 수 있어 제품의 수축결함 및 기포결함을 방지하고, 용탕 내 포함된 개재물을 용이하게 방지하여 주조결함을 방지하고, 우수한 정밀도 및 복잡한 형상의 제품 제조가 가능할 수 있다.Therefore, when the molten metal is filled from the bottom of the mold 30 and moved to the upper riser 50, the initial unstable molten metal and remaining inclusions and impurities are moved upward to remove the product out of the product and the molten metal injected into the riser 50. The gravity is injected into the lower cavity 30 from the riser 50 located at the upper side, and the air bubbles and air contained in the cavity 35 melt can be removed to prevent shrinkage defects and bubble defects of the product, Easily prevent the inclusions included to prevent casting defects, it is possible to manufacture products of excellent precision and complex shape.
한 구체예에서 상기 라이저(50)는 상기 주형(30)의 약 30 부피% 내지 약 120 부피% 크기로 형성될 수 있다. 구체예에서는 약 50 부피% 내지 약 80 부피%의 크기로 형성될 수 있다. In one embodiment, the riser 50 may be formed in a size of about 30% by volume to about 120% by volume of the mold 30. In embodiments it may be formed in a size of about 50% by volume to about 80% by volume.
상기 범위에서 상기 용탕에 포함된 개재물(inclusion)들을 용이하게 제거할 수 있으며, 상기 주형(30)에 잔존하는 기포 및 공기를 용이하게 제거할 수 있다.Inclusions included in the molten metal in the above range can be easily removed, and bubbles and air remaining in the mold 30 can be easily removed.
상기 압력조절수단(60)은 상기 주조챔버(10) 상부에 위치하며 상기 주조챔버(10) 내부의 압력을 조절하여 감압할 수 있다. 한 구체예에서 상기 압력조절수단(60)은 흡입 스크린(64), 진공펌프(미도시) 및 흡입관(62)을 포함할 수 있다. 도 1을 참조하면, 흡입스크린(64)은 주조챔버(10) 상부와 연결되고, 흡입스크린(64)의 일면에는 흡입관(62)이 연결되며, 흡입관(62)은 진공펌프(미도시)와 접속되어 진공펌프의 가동에 의해 주조챔버(10) 내부의 압력을 조절할 수 있다.The pressure adjusting means 60 may be positioned above the casting chamber 10 to reduce the pressure by adjusting the pressure inside the casting chamber 10. In one embodiment the pressure adjusting means 60 may include a suction screen 64, a vacuum pump (not shown) and the suction pipe (62). Referring to FIG. 1, the suction screen 64 is connected to an upper portion of the casting chamber 10, and a suction pipe 62 is connected to one surface of the suction screen 64, and the suction pipe 62 is connected to a vacuum pump (not shown). The pressure inside the casting chamber 10 can be adjusted by connecting and operating a vacuum pump.
상기 흡입 스크린(64)은 상기 압력조절수단(60)에 포함된 진공펌프를 가동시 상기 흡입관(62)에 기체만 통과시키고 상기 충진매체(40)의 흡입을 방지시키는 역할을 할 수 있다.The suction screen 64 may serve to pass only gas through the suction pipe 62 and prevent the suction of the filling medium 40 when the vacuum pump included in the pressure regulating means 60 operates.
상기 진공펌프(미도시)는 상기 주조챔버(10)의 압력을 조절하여 주형(30) 내부의 가스 제거 및 용탕 주입 속도를 조절할 수 있다. 상기 진공 펌프로는 통상적인 것을 사용할 수 있다. 예를 들면, 이온 펌프(Ion Pump) 및 디퓨전 펌프(Diffusion Pump) 등을 사용할 수 있으나, 이에 제한되지 않는다.The vacuum pump (not shown) may adjust the pressure of the casting chamber 10 to control the gas removal and the molten metal injection rate inside the mold 30. As the vacuum pump, a conventional one can be used. For example, an ion pump and a diffusion pump may be used, but the present invention is not limited thereto.
상기 흡입관(62)은 상기 진공펌프의 작동시 상기 주조챔버(10) 내부의 기체를 외부로 배출하여 상기 주조챔버(10) 내의 압력을 감압시킬 수 있다. 이때 상기 주조챔버(10) 내부압력을 감압시키는 속도를 조절하여 상기 용탕의 주입속도를 조절할 수 있다.The suction pipe 62 may reduce the pressure in the casting chamber 10 by discharging the gas inside the casting chamber 10 to the outside during the operation of the vacuum pump. At this time, it is possible to control the injection speed of the molten metal by adjusting the speed of reducing the pressure inside the casting chamber 10.
도 3은 본 발명의 다른 구체예에 따른 이중 주조 장치(100)를 나타낸다. 도 3을 참조하면, 상기 이중 주조 장치는(100)는 원료를 용해하여 용탕을 형성시키는 용해로(70)를 더 포함할 수 있다. 도 3을 참조하면, 구체예에서 용해로(70)는 이중 주조 장치(100)의 하부에 위치하여 이중 주조 장치(100)의 주입관(20)이 용해로(70) 내부의 용탕에 잠입되어, 주조챔버(10)의 감압에 의해 용탕을 주입시킬 수 있다. 구체예에서 주입관(20)은 용해로(70) 내부에 형성된 용탕에 약 3cm 내지 약 10cm 깊이로 잠입될 수 있다. 상기 조건에서 외부 공기가 상기 용탕에 유입되는 것을 최대한 방지하여 주조결함을 방지하면서 상기 용탕의 주입 속도를 용이하게 조절할 수 있다.3 shows a duplex casting apparatus 100 according to another embodiment of the invention. Referring to FIG. 3, the duplex casting apparatus 100 may further include a melting furnace 70 for dissolving raw materials to form a molten metal. Referring to FIG. 3, in the embodiment, the melting furnace 70 is positioned below the dual casting apparatus 100 such that the injection pipe 20 of the dual casting apparatus 100 is immersed in the molten metal inside the melting furnace 70, thereby casting The molten metal can be injected by the reduced pressure of the chamber 10. In an embodiment, the injection tube 20 may be immersed in a melt formed in the melting furnace 70 to a depth of about 3 cm to about 10 cm. Under the above conditions, the injection rate of the molten metal can be easily adjusted while preventing the casting defect by preventing the external air from flowing into the molten metal to the maximum.
한 구체예에서 상기 용해로(70)는 통상적인 것을 사용할 수 있다. 예를 들면, 텅스텐(Tungsten)및 칸탈(Kanthal) 등의 코일(Coil) 타입 발열체가 포함된 전기로를 사용하여 수용된 원료를 가열하여 용탕을 형성할 수 있다.In one embodiment, the melting furnace 70 may be a conventional one. For example, a molten metal may be formed by heating a received raw material using an electric furnace including a coil type heating element such as tungsten and kanthal.
본 발명의 다른 관점은 상기 이중 주조 장치(100)를 이용한 이중 주조 방법에 관한 것이다. 한 구체예에서 상기 이중 주조 방법은 주조챔버(10)를 감압하여 캐비티(35)에 1차 주입하고, 상기 감압을 해제하여 2차 주입하는 단계;를 포함할 수 있다.Another aspect of the present invention relates to a duplex casting method using the duplex casting apparatus 100. In one embodiment, the duplex casting method may include a step of firstly injecting the casting chamber 10 into the cavity 35 by decompressing the pressure, and releasing the second pressure to inject the secondly.
더욱 상세하게는, 충진매체(40)가 충진된 주조챔버(10)를 압력조절수단(60)에 의해 감압하여 외부와의 압력차에 의해 용탕을 주입관(20)을 따라 주형(30) 내부의 캐비티(35)에 1차 주입하고; 상기 캐비티(35)에 1차 주입된 용탕이 응고되기 전에 상기 주조챔버(10)의 감압을 해제하여, 중력에 의해 2차 주입하고, 주조챔버를 해체하여 주형을 분리하는 단계를 포함할 수 있다.More specifically, the casting chamber 10 filled with the filling medium 40 is depressurized by the pressure regulating means 60 so that the molten metal is injected along the injection pipe 20 by the pressure difference from the outside to the inside of the mold 30. First injection into the cavity 35; Before the molten metal first injected into the cavity 35 is solidified, the casting chamber 10 may be decompressed, secondly injected by gravity, and the casting chamber may be dismantled to separate the mold. .
한 구체예에서 상기 이중 주조 방법은 주입관(20)이 장착된 주조챔버(10) 내부에 주형(30)을 넣어 주입관(20)과 결합시키고, 상기 주조챔버(10) 내부를 충진매체(40)로 채운 후 상기 압력조절수단을 통한 감압에 의해 1차 주입할 수 있다.In one embodiment, the double casting method is to put the mold 30 in the casting chamber 10, the injection tube 20 is mounted to combine with the injection tube 20, the inside of the casting chamber 10, the filling medium ( After filling with 40) it can be injected first by decompression through the pressure adjusting means.
이하, 상기 이중 주조 방법을 단계별로 상세히 설명한다.Hereinafter, the duplex casting method will be described in detail step by step.
(a) 용탕 형성단계(a) molten metal forming step
상기 단계는 상기 용해로(70)에 수용된 원료를 용해하여 용탕을 형성하는 단계이다. 상기 용해로(70)로는 전기로(electric furnace)를 사용할 수 있으며, 상기 전기로에 포함된 발열체 코일을 사용하여 가열하여 상기 원료를 용해시킬 수 있으나, 이에 제한되지 않는다.The step is to dissolve the raw material contained in the melting furnace 70 to form a molten metal. An electric furnace may be used as the melting furnace 70, and the raw material may be dissolved by heating using a heating element coil included in the electric furnace, but is not limited thereto.
(b) 1차 주입단계(b) first injection step
상기 단계는 상기 주조챔버(10) 및 상기 주형(30) 사이에 충진매체(40)를 충진한 다음, 상기 압력조절수단(60)을 통하여 상기 주조챔버(10)의 내부 압력을 감압시키는 단계이다. 구체예에서 상기 감압 압력은 약 10-2 torr 내지 약 10-5 torr으로 조절될 수 있다. 상기 조건에서 용탕의 주입 속도를 용이하게 조절하며, 주조결함을 방지할 수 있다.The step is filling the filling medium 40 between the casting chamber 10 and the mold 30, and then depressurizing the internal pressure of the casting chamber 10 through the pressure adjusting means (60). . In embodiments, the reduced pressure may be adjusted to about 10 −2 torr to about 10 −5 torr. Under the above conditions, the injection speed of the molten metal can be easily adjusted, and casting defects can be prevented.
상기 감압된 주조챔버(10)의 주입관(20)을 상기 제조된 용탕에 잠입시킨 다음, 상기 주조챔버(10)와 외부와의 압력차에 의해 용탕이 주입관(20)을 따라 주형(30) 내부의 캐비티(35)에 1차 주입된다. The injection tube 20 of the reduced pressure casting chamber 10 is immersed in the manufactured molten metal, and the molten metal is poured along the injection tube 20 by the pressure difference between the casting chamber 10 and the outside. ) Is first injected into the cavity 35 inside.
한 구체예에서, 상기 주입관(20)은 상기 용해로(70) 내부에 형성된 용탕에 약 3cm 내지 약 10cm 깊이로 잠입되어 용탕이 주입될 수 있다. 상기 조건에서 외부 공기가 상기 용탕에 유입되는 것을 최대한 방지하여 주조결함을 방지하면서 상기 용탕의 주입 속도를 용이하게 조절할 수 있다.In one embodiment, the injection tube 20 is infiltrated into the molten metal formed in the melting furnace 70 to a depth of about 3cm to about 10cm may be injected into the molten metal. Under the above conditions, the injection speed of the molten metal can be easily adjusted while preventing the casting defect by preventing the external air from flowing into the molten metal as much as possible.
한 구체예에서는, 상기 감압시 상기 주조챔버(10)의 감압속도를 조절하여 상기 주형(30)에 주입되는 용탕의 주입속도를 조절할 수 있다. 구체적으로, 반복된 제품의 제조를 통하여 획득한 데이터를 통해 원하는 제품의 형상에 따라 난류(turbulence)를 최소화 할 수 있도록 상기 압력조절수단(60)을 통해 인가되는 감압속도를 조절하여 상기 용탕의 주입 속도를 조절할 수 있다. 예를 들면, 감압속도를 약 0.1cm/s 내지 약 30cm/s로 조절할 수 있다. 상기와 같이 주입속도를 조절시 상기 용탕의 난류(turbulence)현상에 의해 기포가 발생되어 주형(30)의 미세 부위에 상기 용탕의 충진을 방해하여 미성형 되는 등의 주조결함을 방지할 수 있다.In one embodiment, the injection speed of the molten metal injected into the mold 30 may be adjusted by adjusting the decompression speed of the casting chamber 10 during the decompression. Specifically, the injection of the molten metal by adjusting the depressurization rate applied through the pressure adjusting means 60 to minimize turbulence according to the shape of the desired product through the data obtained through the manufacture of repeated products You can adjust the speed. For example, the decompression rate can be adjusted from about 0.1 cm / s to about 30 cm / s. As described above, bubbles are generated by turbulence of the molten metal when the injection rate is adjusted, thereby preventing casting defects such as unmolding by hindering the filling of the molten metal in the mold 30.
다른 구체예에서는, 상기 감압시 상기 주조챔버(10)의 감압속도를 조절하여 상기 1차 주입시 상기 캐비티(35) 상부와 통하여 형성된 라이저(50)에 주입되는 용탕의 주입속도 또한 조절할 수 있다.In another embodiment, the injection speed of the molten metal injected into the riser 50 formed through the upper part of the cavity 35 may be adjusted by adjusting the decompression speed of the casting chamber 10 during the decompression.
(c) 2차 주입단계(c) second injection step
상기 단계는 상기 캐비티(35)에 1차 주입된 용탕이 응고되기 전에 상기 주조챔버(10)의 감압을 해제하여, 중력에 의해 2차로 주입되는 단계이다. 상기 1차 주입은 용탕이 하부에서 상부로 이동인 반면, 2차 주입은 상부에서 하부로 이동하는 것이다.In this step, before the molten metal first injected into the cavity 35 is solidified, the decompression of the casting chamber 10 is released, and the second injection is performed by gravity. The primary injection is where the melt moves from bottom to top, while the secondary injection moves from top to bottom.
한 구체예에서 상기 캐비티(35)에 1차 주입된 용탕은 상기 캐비티(35)의 바깥쪽에서 부터 방향성 응고를 시작하게 된다. 따라서 상대적으로 밀도가 낮은 개재물(또는 불순물)은 상기 캐비티(35)의 표면에 응고되어 용이하게 제거될 수 있다. 또한, 상기 2차 주입되면서 상기 캐비티(35)에 형성된 기공 및 기포가 용이하게 제거될 수 있다.In one embodiment, the molten metal first injected into the cavity 35 starts directional solidification from the outside of the cavity 35. Therefore, the relatively low density inclusions (or impurities) may be easily solidified on the surface of the cavity 35. In addition, pores and bubbles formed in the cavity 35 may be easily removed while the second injection.
다른 구체예에서 상기 주형(30)의 캐비티(35) 상부와 통하는 라이저(50)가 형성된 경우, 상기 주조챔버(10)의 감압 해제시 상기 라이저(50)에 주입된 용탕이 중력에 의해 배출되어 캐비티(35)에 2차 주입될 수 있다. 상기 라이저(50)까지 주입된 용탕이 중력에 의해 상기 주형(30)에 2차 주입되면서 상기 캐비티(35)에 형성된 기공 및 기포가 용이하게 제거될 수 있다.In another embodiment, when the riser 50 communicating with the upper portion of the cavity 35 of the mold 30 is formed, the molten metal injected into the riser 50 is discharged by gravity when the pressure is released from the casting chamber 10. Secondary injection into the cavity 35 can be made. As the molten metal injected up to the riser 50 is secondly injected into the mold 30 by gravity, pores and bubbles formed in the cavity 35 may be easily removed.
(d) 해체단계(d) dismantling stage
상기 단계는 2차 주입된 상기 주조챔버(10)를 해체하여 상기 주형(30) 내부에 형성된 제품을 수득하는 단계이다.The step is to disassemble the second injection chamber 10 to obtain a product formed inside the mold (30).
도 3은 본 발명의 다른 구체예에 따른 이중 주조 장치(100)를 나타낸다. 도 3을 참조하면, 상기 주입관(20), 압력조절장치(60) 및 충진매체(40)는 주조챔버(10a)로부터 용이한 탈부착이 가능하다. 예를 들면, 상기 이중 주조 방법을 이용하여 원하는 제품의 제조가 완료된 다음, 상기 주조챔버(10a)를 분리하여 해체하고 상기 주입관(20), 압력조절장치(60) 및 상기 충진매체(40)는 다른 주조챔버(10b)에 장착되어 재사용이 가능할 수 있어 원가절감 효과를 가질 수 있다.3 shows a duplex casting apparatus 100 according to another embodiment of the invention. Referring to FIG. 3, the injection tube 20, the pressure regulator 60, and the filling medium 40 may be easily detached from the casting chamber 10a. For example, after the manufacture of the desired product is completed using the double casting method, the casting chamber 10a is separated and dismantled, and the injection tube 20, the pressure regulator 60, and the filling medium 40 are removed. Is mounted on the other casting chamber (10b) can be reused can have a cost reduction effect.
이하, 본 발명의 바람직한 실시예를 통해 본 발명의 구성 및 작용을 더욱 상세히 설명하기로 한다. 다만, 이는 본 발명의 바람직한 예시로 제시된 것이며 어떠한 의미로도 이에 의해 본 발명이 제한되는 것으로 해석될 수는 없다.Hereinafter, the configuration and operation of the present invention through the preferred embodiment of the present invention will be described in more detail. However, this is presented as a preferred example of the present invention and in no sense can be construed as limiting the present invention.
여기에 기재되지 않은 내용은 이 기술 분야에서 숙련된 자이면 충분히 기술적으로 유추할 수 있는 것이므로 그 설명을 생략하기로 한다.Details that are not described herein will be omitted since those skilled in the art can sufficiently infer technically.
실시예Example
지름 600mm 이고 높이 800mm인 원기둥 형태의 주입챔버(10)의 하단부에 도 2 (a)와 같은 형태를 갖고, 200mm 길이의 세라믹 재질의 주입관(20)을 설치하였다.A lower portion of the cylindrical injection chamber 10 having a diameter of 600 mm and a height of 800 mm has a shape as shown in FIG. 2 (a) and a 200 mm long ceramic injection tube 20 is installed.
그 다음에 알루미나 모래, 수용성 페놀 수지 및 에스테르계 경화제를 포함하여 제조된 혼련사(mixed sand)를 사용하여, 캐비티(35)를 갖는 주형(30)을 제조하고, 상기 주입관(20) 입구에 덧씌워서 상기 주입챔버(10) 내부에 위치시켰다. 이때 상기 주입관 내경(d1)은 Φ50mm이고, 상기 캐비티 입구 내경(d2)은 Φ25mm의 크기로 형성된 것을 사용하였다. 상기 주형(30)에는 상기 캐비티(35) 상부와 통하는 라이저(50)를 장착하였다. 이때 라이저(50)는 주형(30) 전제부피에 대하여 65 부피%의 크기가 되도록 형성하였다.Then, a mold 30 having a cavity 35 was prepared by using a kneaded sand made of alumina sand, a water-soluble phenolic resin, and an ester curing agent, and formed at the inlet of the injection tube 20. Overlay was placed inside the injection chamber (10). At this time, the injection pipe inner diameter (d1) is Φ50mm, the cavity inlet diameter (d2) was used to form a size of Φ25mm. The mold 30 was equipped with a riser 50 communicating with the upper portion of the cavity 35. At this time, the riser 50 was formed to have a size of 65% by volume with respect to the entire volume of the mold 30.
이때 도 1과 같은 형성된 주형(30)을 상기 주입관(20) 상에 덧씌워 틈새가 발생되지 않도록 하였다. 주입챔버(10)와 주형(30) 사이를 충진매체(40)로 진동을 가하면서 충전하였다.In this case, the formed mold 30 as shown in FIG. 1 was overlaid on the injection tube 20 so as not to generate a gap. The filling chamber 40 was charged while vibrating between the injection chamber 10 and the mold 30 with a filling medium 40.
텅스텐 코일 타입의 발열체를 포함하는 용해로(전기로)(70)를 준비하여 원료를 투입하고 가열하여 용탕을 제조한 다음, 상기 주입챔버(10) 상부에 흡입 스크린(60), 흡입관(62) 및 진공펌프(미도시)를 포함하는 압력조절수단(60)을 장착시킨 후 진공 펌프(미도시)를 작동하여 상기 주입챔버(10) 내부를 10-3 torr의 진공상태로 유지시켰다. 그 다음에 상기 세라믹 주입관(20)을 상기 전기로 내에 제조된 용탕에 50mm 깊이로 잠입토록 하여 상기 주입관(20) 내로 상기 용탕을 1차 주입하여 상기 주형(30) 및 라이저(50)까지 상기 용탕을 주입하였다. 90초 후 진공펌프를 오프(off)하여 1차 상기 주입된 용탕이 응고되기 전에 중력에 의해 상기 라이저(50)까지 주입된 용탕이 중력에 의해 상기 캐비티(35)에 2차 주입되도록 하였다. 120초 후 상기 주입챔버(10)를 이동하여 해체 컨베이어에 위치하여 상기 주형(30) 내 캐비티(35)에 형성된 제품을 수득하였다. 이때, 수득된 제품은 기포, 웜홀 및 미성형 등의 주조결함이 발생하지 않았다.After preparing a melting furnace (electric furnace) 70 including a tungsten coil-type heating element, a raw material is added and heated to prepare a molten metal, and then a suction screen 60, a suction pipe 62, and an upper portion of the injection chamber 10. After mounting the pressure adjusting means 60 including a vacuum pump (not shown) to operate a vacuum pump (not shown) to maintain the interior of the injection chamber 10 in a vacuum state of 10 -3 torr. Then, the ceramic injection tube 20 is immersed in the molten metal produced in the electric furnace to a depth of 50 mm to first inject the molten metal into the injection tube 20 to the mold 30 and the riser 50. The molten metal was injected. After 90 seconds, the vacuum pump was turned off so that the molten metal injected up to the riser 50 by gravity was injected into the cavity 35 by gravity before the first molten molten metal solidified. After 120 seconds, the injection chamber 10 was moved and placed on a disassembly conveyor to obtain a product formed in the cavity 35 in the mold 30. At this time, the obtained product did not cause casting defects such as bubbles, wormholes and unmolded.

Claims (12)

  1. 내부에 공간부가 형성된 주조챔버;A casting chamber having a space formed therein;
    상기 주조챔버 하부에 장착되며, 용탕이 주입되는 주입관;An injection tube mounted below the casting chamber and into which molten metal is injected;
    상기 주입관과 탈부착 가능하도록 연결되며, 캐비티(cavity)를 가지는 주형;A mold that is detachably connected to the injection tube and has a cavity;
    상기 주조챔버 내부 및 상기 주형 사이에 충진되는 충진매체; 및A filling medium filled in the casting chamber and between the mold; And
    상기 주조챔버 상부에 위치하며 상기 주조챔버 내부를 감압하는 압력조절수단;을 포함하여 구성되는 것을 특징으로 하는 이중 주조 장치.And a pressure regulating means positioned on the casting chamber and depressurizing the inside of the casting chamber.
  2. 제1항에 있어서, 상기 주형 내부의 캐비티 상부와 통하여 용탕을 수용하고 캐비티로 배출하는 라이저;를 더 포함하는 것을 특징으로 하는 이중 주조 장치.The duplex casting apparatus according to claim 1, further comprising a riser configured to receive the molten metal through the upper portion of the cavity inside the mold and to discharge the molten metal into the cavity.
  3. 제1항에 있어서, 상기 라이저는 상기 주형의 약 30 부피% 내지 약 120 부피% 크기로 형성되는 것을 특징으로 하는 이중 주조 장치.The apparatus of claim 1, wherein the riser is formed in a size from about 30% to about 120% by volume of the mold.
  4. 제1항에 있어서, 원료를 용해하여 용탕을 형성시키는 용해로;를 더 포함하는 것을 특징으로 하는 이중 주조 장치.The duplex casting apparatus according to claim 1, further comprising a melting furnace for dissolving raw materials to form a molten metal.
  5. 제1항에 있어서, 상기 주입관의 내경은 캐비티의 입구 내경보다 큰 것을 특징으로 하는 이중 주조 장치.The duplex casting apparatus according to claim 1, wherein an inner diameter of the injection tube is larger than an inner diameter of the inlet of the cavity.
  6. 제5항에 있어서, 상기 캐비티의 내경과 상기 주입관의 내경의 비는 약 1:1.1 내지 약 1:3인 것을 특징으로 하는 이중 주조 장치. The apparatus of claim 5, wherein the ratio of the inner diameter of the cavity to the inner diameter of the injection tube is from about 1: 1.1 to about 1: 3.
  7. 제1항에 있어서, 상기 압력조절수단은 흡입 스크린, 진공펌프 및 흡입관을 포함하는 것을 특징으로 하는 이중 주조 장치.The duplex casting apparatus according to claim 1, wherein the pressure adjusting means includes a suction screen, a vacuum pump and a suction pipe.
  8. 충진매체가 충진된 주조챔버를 압력조절수단에 의해 감압하여 외부와의 압력차에 의해 용탕을 주입관을 따라 주형 내부의 캐비티에 1차 주입하고; 그리고Depressurizing the casting chamber filled with the filling medium by the pressure adjusting means to inject molten metal into the cavity inside the mold along the injection tube by the pressure difference with the outside; And
    상기 캐비티에 1차 주입된 용탕이 응고되기 전에 상기 주조챔버의 감압을 해제하여, 중력에 의해 2차 주입되는 단계;를 포함하는 것을 특징으로 하는 이중 주조 방법.Releasing the pressure reduction of the casting chamber before the molten metal first injected into the cavity is solidified and secondly injected by gravity.
  9. 제8항에 있어서, 상기 1차 주입시, 주형 내부의 캐비티 상부와 통하여 형성된 라이저에도 주입되고,According to claim 8, During the first injection, it is also injected into the riser formed through the upper cavity inside the mold,
    주조챔버의 감압 해제시 상기 라이저에 주입된 용탕이 중력에 의해 배출되어 캐비티에 2차 주입되는 것을 특징으로 하는 이중 주조 방법.When the decompression of the casting chamber is released, the molten metal injected into the riser is discharged by gravity and injected into the cavity secondly.
  10. 제8항에 있어서, 상기 방법은 주입관이 장착된 주조챔버 내부에 주형을 넣어 주입관과 결합시키고, 상기 주조챔버 내부를 충진매체로 채운 후 감압에 의해 1차 주입하는 것을 특징으로 하는 방법.The method as claimed in claim 8, wherein the mold is inserted into a casting chamber in which an injection tube is mounted to be combined with the injection tube, and the primary chamber is first injected by decompression after filling the casting chamber with a filling medium.
  11. 제8항에 있어서, 상기 주조챔버를 감압하는 속도를 조절하여 상기 주형에 주입되는 용탕의 주입속도를 조절하는 것을 특징으로 하는 이중 주조 방법.The duplex casting method according to claim 8, wherein an injection speed of the molten metal injected into the mold is controlled by adjusting a speed of depressurizing the casting chamber.
  12. 제8항에 있어서, 상기 주입관, 압력조절수단 및 충진매체는 재사용되는 것을 특징으로 하는 이중 주조 방법.9. The method of claim 8, wherein the injection tube, the pressure regulating means and the filling medium are reused.
PCT/KR2014/004016 2013-05-08 2014-05-07 Double casting method and apparatus WO2014182045A1 (en)

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