Abstract: It is an object to provide a gas cupola for melting a charging material efficiently by a combustion flame of a combustion burner. The gas cupola includes a furnace body having a melting chamber 10 and a molten metal discharge port 11 for discharging the molten metal and a plurality of combustion burners 4 forming a combustion flame 41. The combustion burner 4 melts the charging material 2 in the melting chamber 10 by ejecting the combustion flame 41 to the charging material 2 in the melting chamber 10. Each combustion burner 4 generates a hollow shaped melting portion 42 at the charging material 2 of the melting chamber 10 by the combustion flame 41 ejected from each combustion burner 4. In the cross sectional view of the furnace body 1 taken along a horizontal direction, the combustion burners 4 are arranged so that the adjacently positioned two hollow shaped melting portions 42 overlap with each other.

Abstract: It is an object to provide a gas cupola for melting a charging material efficiently by a combustion flame of a combustion burner. The gas cupola includes a furnace body having a melting chamber 10 and a molten metal discharge port 11 for discharging the molten metal and a plurality of combustion burners 4 forming a combustion flame 41. The combustion burner 4 melts the charging material 2 in the melting chamber 10 by ejecting the combustion flame 41 to the charging material 2 in the melting chamber 10. Each combustion burner 4 generates a hollow shaped melting portion 42 at the charging material 2 of the melting chamber 10 by the combustion flame 41 ejected from each combustion burner 4. In the cross sectional view of the furnace body 1 taken along a horizontal direction, the combustion burners 4 are arranged so that the adjacently positioned two hollow shaped melting portions 42 overlap with each other.

Abstract: A partition member having partition walls arranged in a lattice is disposed in the vicinity of an upper surface of a molten metal mass. The upper surface is divided by the partition walls into a multiplicity of segmental surfaces. A forming starter member is brought into contact with the partition member so that the molten material adheres to a starter surface of the forming starter member, and is then separated from the partition member. The molten metal is drawn from each of the segmental surfaces, and the drawn metal is solidified to form a piece which has a cross sectional shape corresponding to the shape of the starter surface. With the use of forming starter members having respective starter surfaces which are different in shape from each other, it is possible to form pieces having various cross sectional shapes which correspond to the shapes of the starter surfaces.

Abstract: A vacuum casting apparatus secures gas tightness of the die cavity without welding together a straight-tubular stalk and a flange or flanges, thus permitting an excellent quality casting. A flange is mounted on an outer periphery of a stalk, and secured between a gas-tight chamber and a die, forming a recess bounded by the die, a surface of the flange, and an outer surface of the stalk. The space inside the chamber is evacuated to a first degree of vacuum so that molten metal is withdrawn into the stalk and overflows the end of the stalk, and flows into the recess. Molten metal in the recess cools and solidifies to form a gas-tight seal between the stalk and the flange. Then, the space inside the chamber is evacuated to a second degree of vacuum and molten metal is withdrawn through the stalk and into the cavity of the die.

Abstract: A vacuum casting apparatus secures gas tightness of the die cavity without welding together a straight-tubular stalk and a flange or flanges, thus permitting an excellent quality casting. Two flanges are mounted in a mutually spaced-apart relation on an outer periphery of a stalk, and secured between a gas-tight chamber and a die. The gas-tight chamber is fitted on the die from above to form a gas-tight space between the two flanges. The space is evacuated to a pressure close to an inner pressure formed in a cavity of the die during vacuum casting. Thus, air that intrudes into the cavity of the die through small gaps between the flanges and the stalk is reduced, thereby preventing casting defects which might otherwise result. An end of the stalk inserted into the die is also spread to bring an outer periphery of the stalk into close contact with an inner periphery of a flange mounted on the stalk.

Abstract: In a method of vacuum casting wherein when the molten metal previously introduced into a molten metal reservoir is fed into a cavity, the lowest head of the molten metal in the molten metal reservoir is held to be higher than the level of a sprue, so that the cycle time of casting may be shortened and the quality of cast products may be improved. To this end, the interior of the molten metal reservoir is held gas tight while the sprue is opened by a gate member of straight tubular shape.

Abstract: A vacuum casting apparatus includes a plurality of pressure pins arranged in a molding cavity, and at least one pressure pin is located in a portion of the molding cavity farthest from a gate. The pressure pins are operated to pressurize the molding cavity in an order from the pressure pin located farthest from the gate to a pressure pin located nearest to the gate. A cross-sectional area reduced portion can also be formed in a portion of a runner connecting the molding cavity and the molten metal retaining dome. A molten metal in the molding cavity is thereby suppressed from flowing backward into the molten metal retaining dome when being pressurized by the pressure pins, so that the quality of the cast products is improved.

Abstract: In a method of vacuum casting molten metal sucked from a molten metal reservoir into a cavity held under a reduced pressure by opening a gate having been blocking the communication between the molten metal reservoir and the cavity, the trapping of gas and foreign matter in the cavity is effectively prevented. To this end, an accommodation space for accommodating gas and foreign matter is provided in the molten metal reservoir. The accommodation space is provided at a position from which the accommodated matter is not sucked into the cavity.

Abstract: A vacuum casting apparatus of the type wherein a gate mechanism (12 and 10) is closed to form a seal. The interior of a cavity (6) is evacuated by a vacuum pump. The side of the gate mechanism (12 and 10) opposite to the cavity is filled with molten metal. The gate mechanism includes a ring-shaped groove (10e) having a V-shaped cross section positioned on the side opposite to the cavity which extends towards the sealing portion of the gate mechanism (12 and 10). With this arrangement, the molten metal in passage (8) fills the ring-shaped groove (10e) and enters the small clearance which exists in the sealing portion of the gate mechanism. The molten metal solidifies both within the ring-shaped groove (10) and this small clearance formed in the sealing portion. The resulting solidified metal piece has generally a ring shape that can be readily peeled off from the gate mechanism (12 and 10) following die release.

Abstract: A casting method wherein casting cycles are continuously performed with respective molds and a common mass of molten metal accommodated in a container, such that in each casting cycle, the mold cavity is filled with the molten metal through a pouring tube connected at one end to a sprue hole of the mold and immersed at the other end in the molten metal mass, due to a difference between pressures to which the mold and the container are exposed, and wherein the molten metal temperature is estimated from the detected amount of consumption of the immersed tube, and the actual molten metal temperature is regulated, on the basis of a difference between a predetermined desired temperature of the molten metal, and the estimated temperature which changes with the actual temperature.

Abstract: A suction casting apparatus is disclosed, which comprises a ventilating casting die, a chamber box and a surface peat for supporting the casting die and chamber box. The surface plate has a a through hole for passing a stalk therethrough, and its surface is formed with grooves which extend from the through hole to an area outside a die mounting area and inside a chamber box mounting area. External air entering through a sealed clearance between the surface plate and the stalk and combustion gas generated from the casting die are quickly led through the grooves into the chamber inner space to be quickly exhausted to the outside.

Abstract: Disclosed are an aluminum alloy casting having a high strength and a high toughness, and a production process for the same. The aluminum alloy casting comprises silicon (Si) in an amount of 2.5 to 4.4% by weight, copper (Cu) in an amount of 1.5 to 2.5% by weight, magnesium (Mg) in an amount of 0.2 to 0.5% by weight and the balance of aluminum (Al), and a matrix thereof includes a dendrite which has a size of 30 micrometers or less. Since the Si addition amount is suppressed as less as possible and since the size of the dendrite is micro-fined in the aluminum alloy casting, the toughness is improved remarkably. Further, since the Cu and Mg are added in the predetermined addition amounts, the strength is enhanced in the aluminum alloy casting. In addition, a solution treatment which is employed in the production process can further enhance the strength of the aluminum alloy casting.

Abstract: Disclosed are a Ti--Al alloy including aluminum (Al) in an amount of 30 to 38% by weight, nitrogen (N) in an amount of 0.2 to 1.0% by weight, and titanium (Ti), substantially the balance, and a process for producing the same. Since the Ti--Al alloy includes the nitrogen in the predetermined amount, the microstructure of the Ti--Al alloy can be micro-fined and made into a uniform one, and accordingly the shrinkage cavities can be reduced remarkably. Therefore, the strength, the ductility or the like of the Ti--Al alloy can be improved remarkably. With the production process, it is possible to produce the Ti--Al alloy including the nitrogen in the predetermined range.

Abstract: Disclosed are a Ti-Al alloy including aluminum (Al) in an amount of 30 to 38% by weight, nitrogen (N) in an amount of 0.2 to 1.0% by weight, and titanium (Ti), substantially the balance, and a process for producing the same. Since the Ti-Al alloy includes the nitrogen in the predetermined amount, the microstructure of the Ti-Al ally can be micro-fined and made into a uniform one, and accordingly the shrinkage cavities can be reduced remarkably. Therefore, the strength, the ductility or the like of the Ti-Al alloy can be improved remarkably. With the production process, it is possible to produce the Ti-Al alloy including the nitrogen in the predetermined range.

Abstract: A method of controlling electromagnetic casting for carrying out the pouring of molten metal is disclosed which utilizes an electromagnetic force generated by a travelling magnetic field. The apparatus for performing the method is constructed so that a single magnet coil for generating a travelling magnetic field is employed and the input current of one phase of the three-phase alternating current to be applied to the magnet coil is subjected to phase control, whereby the electromagnetic force of the travelling magnetic field is controlled so as to automatically effect compensation for the change of the molten metal level due to the decrease of the amount of molten metal remaining to be poured.