JP5101349B2 - Vertical casting apparatus and vertical casting method - Google Patents

Description

  The present invention is a vertical casting apparatus capable of casting a cast product such as an aluminum alloy from below, and filling the mold cavities with molten metal from below. The present invention relates to a vertical casting apparatus for supplying and filling and a vertical casting method using the vertical casting apparatus.

  When casting a cast product such as a light alloy product, particularly a part that requires strength, a vertical casting apparatus is used to prevent gas entrainment during casting of the molten metal.

  In such vertical casting apparatuses, it is already known to use low-pressure gas as means for supplying molten metal from the molten metal holding furnace to the mold cavities while preventing the mixing of oxides and gas entrainment. (See Patent Document 1). However, the low-pressure gas is effective for quantitatively supplying the molten metal to the mold, but simply using the low-pressure gas has a low casting speed and a low pressure. It was not possible to prevent or sufficiently respond to thin-walled products. Further, in the conventional apparatus, a large amount of molten metal is accommodated in a molten metal holding furnace fixed to the apparatus main body, and the apparatus is enlarged. Further, it is not easy to replenish the molten metal in the molten metal holding furnace fixed to the apparatus main body, and it is very difficult to clean and lubricate the inflow gate of the apparatus main body.

In order to solve the above problems, the present inventors have proposed a method using high-pressure gas pressurization as means for supplying molten metal to a mold cavity (see Patent Document 2). However, when cast stalk is provided in the main body of the apparatus, when the pouring pan is moved for hot water supply, the cast stalk is exposed to the outside air, causing an oxide film or a solidified film, which causes defective products. Was leaving. Moreover, the temperature change of casting stalk is large, and there is a risk of fatigue failure. On the other hand, when the casting stalk is provided in the gas pressurized pouring pot, the conventional pouring pot having a U-shaped vertical cross section is very difficult to attach the casting stalk in a sealed state, and the vibration caused by the movement makes it durable. In addition, since the cross-sectional area of the upper part of the pan is relatively large, the outside air accumulates in such a part, which causes the generation of an oxide film and a solidified film.
JP 58-55166 A Japanese Patent No. 4054051

  In casting by a vertical casting apparatus, in order to cast a high-quality casting product, particularly a thin-walled and large-sized casting product, it is necessary to fill the mold cavity with molten metal at a high speed. Also, in order to prevent the inclusion of oxides and gas entrainment that cause defective defects in castings, and to prevent shrinkage caused by solidification shrinkage, it is effective to fill the molten metal from below and use a sufficient amount of molten metal. It is necessary to replenish with pressure. At that time, in order to reduce trouble during operation, it is necessary to simplify the structure of the cavity and the structure of the entire casting apparatus. Work efficiency and ease of maintenance are also very important factors.

  The object of the present invention is to fill the mold cavities with the molten metal at high speed, effectively pressurize the molten metal in the closed cavities so that there is no generation of sink marks and gas entrainment, and when the pouring pan moves. A vertical casting apparatus capable of easily casting a defect-free cast product without generation of an oxide film and a solidified film generated on the surface of the embedded stalk, and having a high work efficiency and easy maintenance, and the vertical mold The object is to provide a vertical casting method using a casting apparatus.

  As a result of diligent research to solve the above-mentioned problems, the present inventors have eliminated the generation of oxide film and solidified film by improving the shape of the gas pressurized pouring pan, and these castings are free from mixing and gas entrainment. As a result, the present invention has been completed. In addition, by using a gas pressurized pouring pan that can be attached to and detached from the apparatus main body, it is possible to provide a vertical casting apparatus that has a high work efficiency and is easy to maintain and has a low equipment cost. By increasing the height, it is possible to supply the molten metal at high speed, and after the cast molten metal fills the cavity, if the molten metal in such a closed state is effectively pressurized by shortening the pressure transmission distance at multiple locations The present inventors have found that castings can be produced without generation of sinkholes and without inclusion of oxide film and gas entrainment, and the present invention has been completed.

That is, the present invention provides (1) a lower fixed mold and an upper movable mold capable of forming a mold cavity, a closing means for closing a molten metal inflow gate formed in the fixed mold, and a closed mold. A vertical casting apparatus comprising: an apparatus main body having a pressurizing means for pressurizing the molten metal in the mold cavity; and a casting means having a gas pressurizing pouring pot for supplying and filling the molten metal into the mold cavity from below. a is, the gas pressure injection Yunabe, said that one end of a long pan body in the horizontal direction, the hot water supply portion extending upwardly is provided, the other end of the pan body, mounted projecting upwardly A casting stalk communicating with the mold cavity is provided, and the molten metal is present in the hot water supply part before and after casting, so that pressurized gas is not introduced into the pan body, and the gas pressurized hot water pan and the apparatus body can be attached and detached. Gas Insert the end of that casting Stoke provided douche Yunabe the melt inflow gate entrance of the stationary mold, and vertical casting apparatus and forming a sealed structure by mounting the apparatus main body, (2) melt flows The vertical casting apparatus according to the above (1) , wherein the closing means for closing the gate is configured integrally with the pressure stem and has a small diameter portion closing the molten metal inflow gate at the tip, 3 ) A mold opening amount measuring means for measuring the mold opening amount of the fixed mold and the movable mold is provided, and the pressurizing speed of the molten metal by the pressing means is controlled so that the mold opening amount is not more than a predetermined amount. The vertical casting apparatus according to the above (1) or (2) characterized by comprising a pressurizing speed control means, and ( 4 ) a casting means for introducing the pressurized gas of the pressurized pouring pan. Provided with pressurized gas introduction means with gas cylinder and piston By controlling the piston speed, and vertical casting apparatus according to any one of the above it is characterized in that it is configured to control the filling speed in the mold cavity of the molten metal (1) to (3), ( 5 ) It relates to the vertical casting apparatus according to any one of the above (1) to ( 4 ), wherein the casting stalk includes a heating means.

The present invention also includes ( 6 ) casting a molten metal into a mold cavity through a casting stalk from a gas pressurized pouring pan using the vertical casting apparatus according to any one of (1) to ( 5 ). Is a casting method in which the molten metal inflow gate formed in the fixed mold is closed by the closing means after the inside of the cavity is filled, and then the molten metal in the mold cavity is pressurized by the pressing means, and the molten metal inflow gate is closed. After clogging with the means, immediately release the gas pressure in the gas pressurized molten metal pan to the atmosphere and remove it from the main body of the equipment, supply the necessary molten metal to the gas pressurized molten metal next time, and attach it to the main body of the equipment again. The vertical casting method characterized by preparing for the next casting, and ( 7 ) the gas pressure in the gas pressurized hot water pouring pan is adjusted to 1 kg / cm ² or more and is cast at high speed in a short time. and vertical casting method according to (6), which, 8) castings, about vertical casting method according to (6) or (7), wherein the thin-walled light metal alloy which is large castings.

  The vertical casting apparatus of the present invention includes a lower fixed mold and an upper movable mold capable of forming a mold cavity, a closing means for closing a molten metal inflow gate formed in the fixed mold, and a closed mold. An apparatus main body having a pressurizing means for pressurizing the molten metal in the mold cavity, and a casting means having a gas pressurized pouring pot for supplying and filling the molten metal into the mold cavity from below. In the casting apparatus, the gas pressurized pouring pan is provided with a hot water supply portion extending upward on one side of the pan body, and on the mold cavity attached to the other side of the pan body so as to protrude upward. The vertical casting apparatus of the present invention is not particularly limited as long as it is configured as a vertical casting apparatus provided with a casting stalk that communicates and the molten metal is present in the hot water supply part before and after casting. Membrane development Is suppressed, these mixed and gas entrainment free castings can be particularly suitably casting large castings with thin. And although it does not specifically limit as this casting, A light metal alloy, especially an aluminum alloy with a large solidification shrinkage are preferable. Since aluminum shrinks by about 7% when solidified, the casting apparatus and casting method of the present invention, which can prevent the formation of shrinkage nests, are particularly thin and large-sized from molten metal made of light metal alloy such as aluminum alloy that has large solidification shrinkage. The present invention can be applied particularly advantageously when casting a cast product.

  As described above, the gas pressurizing pouring pan in the casting means is provided with a hot water supply portion extending upward on one side of the pan body, and the above-mentioned gold attached to the other side of the pan body so as to protrude upward. Casting stalk communicating with the mold cavity is provided, and the molten metal is present in the hot water supply part before and after casting, and includes a lid that seals the hot water supply port at the tip of the hot water supply part. When the gas pressurized pouring pan and the device main body are detachable, insert the tip of the casting stalk provided in the gas pressurized pouring pan into the molten metal inflow gate inlet of the fixed mold and attach it to the device main body. Form a sealed structure.

  The hot water supply part provided in the pan body may be formed integrally with the pan body or may be a hot water pipe attached to the upper part of the pan body. In the case of integral molding with the pan body, the hot water supply unit may have the same cross-sectional shape as the pan body, but is preferably smaller than the cross-sectional area of the pan body. That is, if it demonstrates using FIG. 1, although the vertical cross section perpendicular | vertical to the paper surface of the pan main body 7a and the cross section of the hot water supply part 7b may be a thing of the same shape, the cross-sectional area of a hot water supply part is the vertical cross-sectional area of a pan main body. A smaller one is preferred. It should be noted that extending upward means preferably extending upward at an angle of 30 ° or more, more preferably 45 ° or more, and particularly preferably 90 °. The cross-sectional area of the hot water supply section is smaller than that of a conventional pouring pot having a U-shaped vertical cross section, and the volume of the gas section can be reduced, so that the gas pressure can be increased, and the determination to the mold cavity is possible. This makes it possible to supply a molten metal, increase the supply speed, and shorten the shot time lag, enabling high-quality casting and casting of a thin and large-sized cast product. Furthermore, by using such a pouring pan, the production cycle time is shortened, so that the productivity is improved.

  Moreover, the casting stalk provided in the pan body is preferably provided at the end (the other side) opposite to the hot water supply portion, and the lower end of the casting stalk is located at the lower part of the pan body. Moreover, the cast stalk and the mounting position of the pan body are located below the hot water supply port at the tip of the hot water supply unit. In this way, the hot water supply section and the cast stalk are provided apart from each other, and the distance from the hot water supply port to the lower end of the cast stalk is long, so there is almost no possibility of gas, oxide film, etc. entering the cast stalk.

  Further, the gas pressurized hot water pan of the present invention is configured so that the molten metal exists in the hot water supply part before and after casting, and no gas is introduced into the pan body, as described above, the cross-sectional area of the hot water supply part is conventionally Therefore, it is possible to suppress generation of an oxide film as much as possible.

  In the gas pressurized hot water pan as described above, since the molten metal can be introduced from the hot water outlet of the gas pressurized hot water pan with the lid opened (removed), for example, using a hot water ladle, the molten metal can be replenished very easily. Can be performed. Moreover, since the gas pressurization pouring pan can be removed and the inflow gate of the apparatus main body can be cleaned and sprayed for lubrication, it is very easy to perform maintenance.

  Such a pressurized gas pouring pan and / or cast stalk is preferably provided with a heating means to maintain the molten metal temperature, thereby suppressing the generation of a solidified layer, good hot water circulation and poor casting products. Generation can be suppressed as much as possible.

  Also, as mentioned above, the capacity of the gas pressurized hot pot is such a capacity that the molten metal exists in the hot water supply section before and after casting, from the viewpoint of preventing the enlargement of the apparatus and the ease of transporting the gas pressurized hot pot. For example, it is preferable that the capacity is one to three times of casting by introducing the molten metal into the gas pressure pouring pot once, and more preferably the capacity capable of being cast once. By making the capacity that can be cast once, the amount of molten metal in the pouring pan at each casting is always constant, so there is no need for pressure correction, and continuous filling can be performed more easily and oxidation. Stable operation is possible by suppressing mixing of objects and gas entrainment. That is, in the case of a capacity for multiple times, the liquid level at the time of each casting is different, and it is necessary to make a fine adjustment of the pressure. There is no need to make any adjustments.

  Moreover, it is preferable that the casting means has a vacuum suction mechanism that vacuum-sucks and fills the molten metal in the gas pressurization pouring pan by vacuuming the gas in the mold cavity in addition to the gas pressurization pouring pan. As a result, the mold cavity can be filled with the molten metal at a high speed, and the gas in the mold cavity can be discharged to prevent the gas from being entrained. This vacuum suction can be performed through a gas discharge passage which will be described later.

  The mold cavity is preferably a mold cavity capable of casting a thin and large-sized cast product, and includes a cavity product section and a cavity hot water reservoir, and the cavity hot water reservoir is located above the molten metal inflow gate. More preferably, it is composed of a first hot water reservoir and one or more cavity second hot water reservoirs located near the end of the cavity product product portion on the opposite side of the first hot water reservoir. And a cavity product part and a cavity 1st hot water reservoir communicate with each other via a side gate, and the cavity first hot water reservoir preferably has a larger volume than a cavity 2nd hot water reservoir. .

  The lower fixed mold is formed with a communicating portion between a casting stalk for filling and supplying molten metal from a lower pouring pot and a cavity first hot water reservoir portion, and a molten metal inflow gate is provided in the communicating portion. ing. The shape of the molten metal inflow gate is not particularly limited. However, in view of ease of processing or the like, a shape having a circular cross section is usually preferable. In this case, the inner diameter of the circular molten metal inflow gate is configured to be smaller than the inner diameter of the stalk. It is preferable to keep it. By configuring in this way, the molten metal filled and supplied from below can be ejected into the cavity first hot water reservoir, and, as will be described later, the molten metal is poured into the stalk that contributes to defective casting products. It is possible to prevent the oxide film on the surface of the molten metal, the oxide film generated by contact with the outside air on the inner surface of the stalk when the pouring pan is detached, and the chill layer (solidified layer) generated by cooling from being mixed into the product.

  The closing means for closing the molten metal inflow gate formed in the fixed mold may be any means as long as it has a mechanism capable of closing the molten metal inflow gate. For example, the circular molten metal inflow gate can be opened and closed. In this case, the diameter of the insertion portion of the closing pin into the circular molten metal inflow gate is made slightly smaller than the inner diameter of the circular molten metal inflow gate. It is preferable from the viewpoint of occlusion and sealing. It is preferable to hold the closing pin so that it can move forward and backward in a liquid-tight manner with respect to the movable mold. In the case of being held slidably densely, a closing pin can be provided coaxially and slidably in a liquid-tight manner at the center of the pressure stem. Further, the closing means may be configured integrally with the pressurizing stem and may have a small diameter portion that closes the molten metal inflow gate at the tip.

As described above, when the pressurizing stem and the closing pin are disposed in the movable mold above the circular molten metal inflow gate, the circular cavity first hot water reservoir portion formed in a state in which they are retracted (raised). The diameter of the inlet is made larger than 1.4 times the diameter of the circular molten metal inflow gate, and the ceiling height of the hot water reservoir at the upper limit of the pressure stem and the closing pin is ejected from the circular molten metal inflow gate. It is preferable that the cavity first hot water reservoir is configured to be 10 mm or more higher than the height of the molten metal jet. Thus, when the diameter of the inlet of the hot water reservoir is 1.4 times or more the diameter of the circular gate, the height h of the molten metal jet is approximately v for the passage speed of the molten metal in the circular gate and g for the acceleration of gravity. when a, ^{h =} v 2 / since 2g can be determined by the equation, when the early speed casting velocity v = 1.4 m / sec in the general range, ejection height h = 1. 4 ² /2g=0.1=100 mm.

  That is, if the ceiling height is set to 100 + 10 = 110 mm, the jet of the hot water will not collide with the ceiling, a free surface will be formed, the oxide film on the surface of the molten metal will be confined without flowing back, and the gas of the Entrainment can also be prevented.

  For example, the pouring / filling speed of the molten metal varies depending on the shape of the product, but generally the initial passing speed in the circular gate is preferably 1.0 to 1.4 m / sec. The height is normally about 50 to 100 mm, but when the height of the ceiling of the first cavern is higher than the height of the molten metal jet by 10 mm or more, a free surface was formed and remained on the hot water surface. The oxide film also remains on the surface, and the gas remaining in the upper part of the hot water reservoir is still contained and does not flow downward. There is no gas involved. On the other hand, if the jet velocity is low, it will not collide with the ceiling and there will be no gas entrainment, but the casting time will be longer, the speed at which the molten metal will flow through the cavity product will become slower, and cooling solidification will progress during this time, causing resistance. Increases, the flow velocity further decreases, and the molten product is insufficiently filled in the cavity product part, and even if the pressure is applied, the pressure transmission is poor and the possibility of occurrence of shrinkage increases. Therefore, when the molten metal fills the first hot water reservoir and begins to enter the product portion, it is preferable to increase the gas pressure in the pouring pan and adjust the casting speed so that the casting speed is as fast as possible. At this time, the first hot water reservoir is filled with molten metal, and this acts as a resistance so that the flow of the inflow gate does not entrap the oxide film or gas remaining on the ceiling. There is also a method of using a gas cylinder to perform this continuous control.

  When supplying the molten metal with high-pressure gas, the casting speed is increased and the molten metal is less cooled and solidified in the cavity, and the driving force can fill the molten product into a narrow part of the cavity product part with high resistance. Even if the filling is insufficient, there is no problem because the volume is small and the filling can be performed by sufficient pressurization such as a pressure stem.

  As described above, by forming the cavity first hot water reservoir in the cavity, the oxide film and gas entrainment existing at the uppermost portion of the hot water reservoir when the closing pin and the pressure stem are advanced (lowered). The layer stays at the upper end of the cavity first hot water reservoir without being extruded, and does not enter the cavity product part. A small amount of oxide film generated on the surface of the Stoke inner bath jumps into the cavity 1st hot water reservoir at the tip of the jet and does not flow out to the cavity product section through the side gate. It will not be mixed, so there will be no defects in casting products and variations in strength.

  Next, by pressurizing the molten metal filled in the closed mold cavity, it is possible to cast a cast product in which no shrinkage occurs during solidification and gas is not entrained by a jet. As a pressurizing means for pressurizing the molten metal in the closed mold cavity, it is slidably provided on the movable mold above the first hot water reservoir of the cavity, and a closing pin is slidable in the center. The pressurizing stem provided and the cavity first hot water reservoir are slidably disposed on the movable mold above the cavity second hot water reservoir located at a position separated from the cavity product portion. A pressure pin can be specifically exemplified. It is preferable to provide a plurality of pressure pins. The diameter is preferably 2/3 to 1 times the depth of the cavity second hot water reservoir. Further, these pressure stems and pressure pins are preferably used in combination. In this way, by pressurizing the molten metal from the pressure stem and the plurality of pressure pins located at separate positions, the pressure transmission distance to the molten metal in the cavity is shortened, so that the pressure is uniformly transmitted to the cavity product part. Therefore, it is possible to cast a cast product in which no shrinkage occurs during solidification with a small pressure. In addition, the pressure transmission distance of the molten metal in the cavity product part is further shortened by arranging the pressure stem and the pressure pin at appropriate positions according to the form of the product, and the pressure transmission is made more uniform and sufficient. In addition, it is possible to prevent the formation of a shrinkage nest with a smaller pressure.

  In conventional casting apparatuses, in general, in order to cast a cast product in which no shrinkage occurs during solidification, the pressurizing means of the molten metal by the pressurizing means is increased and rapidly pressurized. In this case, the pressure transmission is too good, the mold opening force becomes large, burrs are blown, and the mold clamping force needs to be increased. However, if the pressurization rate is slowed down, it will not catch up with the solidification shrinkage of the molten metal, and a sinkhole will be generated. On the other hand, according to the present invention, uniform and sufficient pressure transmission can be performed even with a small mold clamping force that can prevent burrs from being blown. it can. As described above, in the present invention, the pressurization speed is controlled by performing program control so that the advancement speed of the pressurization stem and pressurization pin during pressurization becomes a speed adapted to the solidification contraction speed of the molten metal in the cavity product part. By adjusting it, it is possible to prevent the formation of sink marks while preventing burrs from being blown with a press device with a small clamping force. For example, the pressure and pressurizing speed for the molten metal during solidification shrinkage where Pascal's principle does not work Is controlled in accordance with the solidification rate within the range where burrs are not blown, so that a device with a small clamping force of 1/3 to 1/5 of the conventional high pressure method can be used. It is possible to obtain a cast product having a dense structure without gas entrainment.

  As an example of a method for detecting the minute mold opening amount, an example in which a short stroke mold clamping cylinder 30 such as a gate lock system as shown in FIG. 8 is used to secure a mold clamping force can be given. In this case, if the distance between the tip of the mold clamping piston 31 and the bottom surface of the mold clamping cylinder 30 is shortened to h, and the mold opening amount reaches δ when the molten metal is filled and pressurized, the mold opening amount is It is absorbed by the elongation of the tie bar of the mold clamping device and the deformation amount of the platen and the retraction amount of the piston 31 of the mold clamping cylinder 30. If the ratio of the retraction amount of the piston 31 is α, the oil in the mold clamping cylinder 30 is compressed by α × δ ÷ h.

Since the compression ratio of the oil is 5.6 × 10 ⁻⁵ / (kg / cm ³ ),
The pressure increases by Δp = α × δ ÷ (h × 5.6 × 10 ⁻⁵ ).
Assuming that the deformation sharing rate α = 1/3, the mold opening amount δ = 0.1 mm, and the distance h from the tip of the piston 31 to the bottom surface of the clamping cylinder 30 is 30 mm,
Δp = (1/3) × 0.1 ÷ (30 × 5.6 × 10 ⁻⁵ ) ≈20 kg / cm ²
Thus, a mold opening amount of 0.1 mm can be sufficiently detected by oil pressure fluctuation. There are many other methods for detecting the mold opening amount, and the present invention is not limited to this method.

  In addition, in the case of vertical casting methods such as squeeze casting, if the pressure applied by the acurad pin (center pin) is accelerated, the casting plunger will be pushed down. Since pressure is applied after the pressure transmission to the plunger has decreased, solidification of the molten metal in the cavity progresses during that time, and a large pressure is required for replenishing the molten metal. However, in the present invention, since the present invention is provided with a means for closing the molten metal inflow gate, it is possible to replenish and fill the molten metal by pressurizing from the stage where solidification is still progressing immediately after the gate is closed. In addition, since the pressure is applied by the pressure stem and a plurality of pressure pins arranged at predetermined positions, the pressure transmission distance is short, and the pressure is uniform and charged with a small pressure. It can be performed Do refill packing. As a result of the pressure being reduced in this way, the mold clamping force of the mold can be reduced, and the costs of the mold clamping device and the mold can be kept low. In addition, this casting speed and pressurization start speed are faster than squeeze casting, thin wall casting is also possible, good heat transfer is maintained by maintaining contact with the mold surface of the molten metal, cooling time is short, crystal The quality is improved, the production cycle time is shortened, and the productivity is improved.

  Further, in the vertical casting apparatus of the present invention, a gas discharge passage capable of discharging the gas existing in the cavity when the molten metal is filled in the mold cavity, and a gap for the molten metal solidification zone communicated with the gas discharge passage. Those having the following are preferred. The gas discharge passage is preferably configured by a gas discharge hole penetrating through the movable mold and a gas discharge gap. The molten metal solidification zone gap is preferably provided in the vicinity of the gas discharge passage, and particularly preferably close to the pressurizing means. As the gap for the molten metal solidification zone, for example, after discharging the gas in the cavity from the gas discharge passage, the molten metal can be solidified in the gap that becomes the molten metal solidification zone. Any air gap can be used as long as it can seal and close the inside of the cavity, and simply by providing such a gap for the molten metal solidification zone, an air vent valve, a filter, etc. are provided and a complicated switching valve or The inside of the cavities can be easily sealed and closed without using a valve, and there is no need for complicated operations such as pressure adjustment when the casting apparatus is in operation. The device can be said to be very practical. In addition, the hot water inlet of the pouring pan can be sealed easily so that gas does not leak with a dedicated lid, and the area of the docking surface between the upper surface of the casting stalk and the lower surface of the inlet gate of the fixed mold is small. The pressure seal that prevents the pressurized gas from leaking can be easily done.

  Specifically, the molten metal solidification zone gap communicates with the gas discharge passage through a gas discharge gap formed between the outer peripheral surface of the pressure stem and / or the pressure pin and the inner peripheral surface of the movable mold. The molten metal solidification zone gap can be exemplified, and the molten metal solidification zone gap is provided concentrically with the pressure stem / or the pressure pin, and from the diameter of the pressure stem and / or the pressure pin. In addition, a gap that becomes a molten metal solidification zone having an inner diameter larger by 1 to 5 mm and a depth (length) of about 10 to 40 mm can be specifically exemplified. In this way, by setting the outer diameter of each hot water pool portion to be slightly larger than the outer shape of the pressure stem and the pressure pin, the solidified layer formed on the outer peripheral wall of each hot water pool portion can be increased by the pressure stem / While being pushed into the product by the pressure pin, the pressure resistance of the pressure stem and the pressure pin can be reduced. As described above, when the gap for the molten metal solidification zone is designed to have a size that matches the temperature of the molten metal and the casting speed, the hot water is cooled and solidified in the gap when the molten metal is filled. Never invade.

  Further, the gas discharge gap preferably has a structure or size that does not allow the hot water to flow in. For example, the gas discharge gap is provided concentrically with the pressure stem and / or the pressure pin, and the pressure stem and / or A gas discharge gap having an inner diameter that is about 0.4 to 1.0 mm larger than the diameter of the pressure pin can be specifically mentioned. When the mold cavity is evacuated, in order to prevent intrusion of air, the parting surface is not provided with gas discharge holes and gas discharge passages. A gas exhaust groove connected to the gas exhaust port is provided to prevent air from leaking into the mold cavity from outside the mold.

  By the way, when the casting start speed of the molten metal by the combined use of the gas pressurized hot pot and the vacuum suction mechanism is an optimum value of 1.0 to 1.4 m / sec, the molten metal provided close to the outer periphery of the pressure stem and the pressure pin. The air resistance in the two-stage gaps such as the solidification zone gap and the gas discharge gap is increased, but the purpose of installing the molten metal solidification zone gap and the gas discharge gap by appropriately selecting the number and arrangement of the pressure pins. Can be achieved. That is, those skilled in the art can easily design a structure in which the hot water is cooled and solidified in the melt solidification zone gap having a two-stage gap and does not enter the gas discharge gap narrower than the melt solidification zone gap. Also, in order to cool and solidify the hot water in the gap for the molten metal solidification zone, a material with good heat conduction, such as beryllium copper, is used for the pressure stem and pressure pin, and the inside can be cooled with water. You can also.

  As described above, in the vertical casting apparatus of the present invention described above, the structure of the gas discharge system around the pressure stem and the pressure pin is simple, and the occurrence of trouble during operation is reduced. In addition, by combining gas pressurization and a vacuum suction mechanism in a sealed small-volume pouring pan, it is possible to cast a large thin product by filling the mold cavity at high speed, The hot water flows into the narrow molten metal solidification zone gap, so that it solidifies and stops there and does not enter the gas discharge gap passage. In addition, by increasing the depth of the cavity 1st hot water reservoir, the stroke of the pressurization stem can be lengthened, and a sufficient volume of molten metal for refilling and coagulation shrinkage in the cavity product part can be obtained. In addition, it is possible to obtain a strong casting with a denser structure by adding pressure to reduce the crystal by increasing the cooling rate. Also, close the circular gate with a closing pin slightly smaller than the inner diameter of the circular gate, release the gas pressure in the pouring pan to the atmosphere, quickly lower it, and let the air flow from the tip of the casting stalk at the circular gate inlet As a result, the molten metal in the stalk is quickly returned to the pouring pan to prevent troubles due to solidification fixation in the stalk.

  In addition, when the mold is opened, the pouring pan is moved so that cleaning of the inflow gate, cooling of the mold surface, and spraying for lubrication can be performed easily and safely.

  In addition, in the casting apparatus of the present invention equipped with a pressurized gas pouring pan and a vacuum suction mechanism, when filling molten metal into the mold cavity, the gas in the cavity is almost completely discharged, and at the same time, the circular gate is closed after filling. Therefore, the necessary and sufficient pressure can be applied with a small pressure, so it can be handled with a clamping force of 1/3 to 1/5 that of the conventional high pressure method, and the cost of the casting apparatus is greatly reduced, and the productivity is also high. Since it is good, the cost of the casting can be greatly reduced. In addition, since the molten metal is supplied directly from the bottom of the pouring pan, the oxide film is not mixed in, and the passage is short, so there is little generation of a solidified layer, and the cavity has an appropriate height at the exit of the circular gate. By providing the first hot water reservoir, the jet flow does not collide with the ceiling, gas entrainment can be eliminated, and a slight remaining oxide film or solidified layer can be retained in the cavity first hot water reservoir. As a result, a cast product having a dense structure free of impurities can be obtained. Furthermore, as the hot pot is small and the gas pressure can be increased, a high casting speed can be secured, thin-wall casting becomes possible, and by moving the hot pot, it is easy to replenish the molten metal and the equipment cost is reduced. In addition, the arrangement and operation of the apparatus become easy.

Further, the vertical casting method of the present invention is a casting method using the vertical casting apparatus, in which the molten metal is cast into the mold cavity through the casting stalk from the gas pressure pouring pot, and the molten metal fills the cavity. After that, it is not particularly limited as long as it is a vertical casting method in which the molten metal inflow gate formed in the fixed mold is closed by the closing means, and then the molten metal in the mold cavities is pressed by the pressing means. The hot water inlet of a gas pressurized hot pot that has received molten metal for one or more times of pouring is sealed and sealed with a special lid, and a gas pressure of preferably 1 kg / cm ² or higher is applied to the hot water pot to add the hot water in the hot pot. The molten metal is cast into the mold cavity through casting stalk. Subsequently, after filling the cavity with molten metal, the molten metal inflow gate provided in the fixed mold is closed with a closing means, and then the molten metal in the mold cavity is pressurized with a pressure means (pressure pin), A cast product in which no shrinkage occurs at the time of solidification and no gas is entrained, preferably a thin and large cast product of a light metal alloy is cast.

  At the retreat position of the pressure pin, the filling of the molten metal into the mold cavities is started, the flow rate of the hot water is decelerated at the cavity second hot water reservoir, and the gas in the mold cavities is discharged from the gas discharge gap. It is preferable that the molten metal solidification zone gap is cooled and solidified, and after the molten metal is filled in the mold cavity, the molten metal in the hot water reservoir is pressurized by advancing one or more pressure pins. The pressure transfer distance by reducing the gas entrainment by performing vacuum degassing from the gas discharge gaps adjacent to the plurality of molten metal solidification zones and pressurizing the molten metal with a pressure stem and a plurality of pressure pins Is preferably shortened. By this replenishment filling, the contact of the molten metal with the mold surface is maintained, good heat transfer is maintained, the cooling rate is high, the coarsening of the crystal is prevented, and a small crystal structure is formed. When the molten metal is solidified and replenishment filling is completed, the movable mold is raised by the movable platen after a short cooling time, and the product material lifted together with the movable mold is moved by the pressure stem, the pressure pin and the extrusion pin. And extruding with an extruding pin and taking out the product material by extracting from the pressurizing pin and pressurizing pin, so that there is no generation of shrinkage and gas entrainment, and no dense oxide or solidified film is mixed. A cast product can be obtained. Further, since this operation is repeated each time, the solidified molten metal in the molten metal solidification zone gap is removed each time, and the gas discharge passage is not clogged. In addition, when sealing the upper surface of the casting stalk of the movable gas pressure pouring pot and the lower surface of the circular gate entrance of the fixed mold, the contact area is small and the sealing can be easily performed.

  After closing the molten metal inflow gate with the closing means, immediately release the gas pressure in the gas pressurized molten pan to the atmosphere and remove it from the device body, supply the necessary molten metal next time, attach it to the device body again, It is preferable to prepare for the next casting. Thereby, it can cast very efficiently using one gas pressurization pouring pot. In addition, although the lid can be opened without removing the pouring pot and the next molten metal can be supplied, it is usually necessary to clean the inflow gate, and it is preferable that the molten metal pot be detached and moved. Also, after closing the molten metal inflow gate with the closing means, releasing the gas pressure to the atmosphere, pulling down the molten metal pan, flowing air from the tip of the casting stalk, and dropping the molten metal in the casting stalk more quickly Further, it is possible to prevent the molten metal from being cooled and solidified and fixed at the inlet gate entrance, and to work more efficiently.

  Hereinafter, the vertical casting apparatus for manufacturing an aluminum wheel will more specifically describe the present invention. However, the vertical casting apparatus of the present invention can be used for manufacturing a cast product other than an aluminum wheel. The technical scope of the invention is not limited to this example. The present invention is also applicable to a vertical casting apparatus in which a cavity product part is provided via a side gate as described in JP-A-2003-266168, for example.

  FIG. 1 is a schematic longitudinal sectional view of a vertical casting apparatus according to the present invention, and FIG. 2 is a view when a special type pressure stem in which the closing pin and the pressure stem of FIG. 1 are integrated is used. FIG. 7 is an explanatory view showing a working state of the vertical casting apparatus of the present invention shown in FIG.

  The casting apparatus of the present invention shown in FIG. 1 has a fixed mold 1 attached to a horizontal fixed platen 3 at the bottom of the casting apparatus, a horizontal mold 5 fixed to the fixed mold 1, and moved up and down to close the mold. A movable mold 2 attached to a horizontal movable platen 4 at the upper part of the casting apparatus through a movable mold holder 6 and capable of opening the mold, and a gas pressure pouring pot 7 located below the fixed platen 3 It has. A mold cavity 10 is formed by the fixed mold 1, the horizontal mold 5 fixed to the fixed mold 1, and the movable mold 2.

  A casting stalk 15 is inserted and pressed through the stationary platen 3 at the inlet of the stationary mold 1 and the molten metal inflow gate 11, and above the casting stalk 15 from the casting stalk 15. A molten metal inflow gate (circular gate) 11 for ejecting the molten metal 8 is provided. When pressurized gas is fed from the pressurized gas inlet 27 and the inside of the mold cavity 10 is depressurized by a vacuum suction mechanism (not shown), the molten metal 8 in the pouring pan 7 is pushed up in the casting stalk 15. The mold cavity 10 is filled through the molten metal inflow gate 11 of the fixed mold 1. The casting speed at this time is adjusted by adjusting the gas pressure in the pouring pan 7 and the degree of vacuum in the mold cavity 10 so that the passing speed of the molten metal inflow gate 11 is high and jets upward. It is controlled by doing.

  The hot water pouring pan 7 has a hot water supply portion 7b extending vertically upward on one side of a pan body 7a that is long in the horizontal direction, and has a lid 34 that seals the hot water supply port at the tip of the hot water supply portion 7b. In addition, a casting stalk 15 communicating with the mold cavity 10 is provided vertically upward at the end opposite to the side where the hot water supply part 7b of the pan body 7a is provided. At this time, the lower end of the casting stalk 15 is located at the lower part of the pan body 7a, and prevents gas, oxide film, and the like from entering the stalk. Further, the molten metal is present in the hot water supply section 7b from before casting (FIG. 1) to after casting (FIG. 5).

  Above the molten metal inflow gate 11, a closing pin 13 driven by a hydraulic cylinder 24 and a pressure plunger (pressure stem) 14 driven by a hydraulic cylinder 17 are provided. After the molten metal 8 is completely filled (filled) into the mold cavity 10 by the gas pressurizing and pouring pan 7 and the vacuum suction mechanism, the closing pin 13 is advanced by the hydraulic cylinder 24 to close the molten metal inflow gate 11 and immediately thereafter. The pressurizing plunger 14 is advanced by the hydraulic cylinder 17, and the molten metal corresponding to the solidification shrinkage volume in the mold cavity 10 is pressurized and supplied from the hub portion hot water reservoir (cavity first hot water reservoir) 12. In this case, the mold cavity 10 is filled with the molten metal 8 by the casting means without using the pressure plunger 14, so that the stroke of the pressure plunger 14 and the pressure pin 20 described later is very short. In addition, with this casting method, the molten metal can be supplied to the mold cavity 10 at a high speed, and a cast product that does not contain a solidified layer, oxide film, or gas can be cast. .

  One or two or more small rim hot water reservoirs (cavity second hot water reservoirs) 19 are formed at the upper end of the mold cavity 10. A rim pressure pin 20 driven by the cylinder 26 is introduced to pressurize the molten metal in the mold cavity 10. That is, together with the pressurizing plunger 14, these pressurizing pins 20 are extruded, and the molten metal of the mold cavity 10 is pressurized via the cavity 2 hot water reservoir 19. The outer diameter of the pressure pin 20 is configured to be slightly smaller than the diameter of the inlet of the rim portion hot water reservoir 19.

  In addition, an ambient gas passage (groove) 22 a is provided on the lower surface of the movable mold 2 so as to surround the outer periphery of the mold cavity 10, and the outside of the machine that flows from the mating surface of the movable mold 2 and the horizontal mold 5. Introducing gas from. This ambient gas passage 22a communicates with the mold cavity 10 on one side via a molten metal solidification gap 10d consisting of an overflow hot water reservoir 10d and a thin gap, and on the other hand, a movable metal via the gas passage 22. It communicates with a vacuum chamber 21 provided inside the mold 2. The vacuum chamber 21 is provided with a gas passage 23 penetrating the movable mold holder 6, and vacuum suction can be performed from the gas passage 23.

Next, the operation of the above-described vertical casting apparatus will be described.
As shown in FIG. 1, when the gas pressurized pouring pan 7 is sealed by the lid 34 and the tip of the casting stalk 15 is brought into close contact with the fixed mold, the gas pressurized pouring pan 7 is fed into the gas pressurized pouring pan 7 through the pressurized gas inlet 27. Due to the gas pressure applied to the molten metal surface of the pressurized gas and the suction by the vacuum suction mechanism from the gas passage 23, the molten metal in the gas pressurized pouring pan 7 is filled into the mold cavity 10 through the casting stalk 15. (Figure 3). When the flow of the molten metal in the mold cavity 10 stops, it is detected as a filling completion signal, and the closing pin 13 is immediately advanced and inserted into the molten metal inflow gate 11 to close it (FIG. 4). At this time, since the molten metal is completely melted at a high temperature and the gas volume of the hot water supply section 7b is small, the pressurized gas can be used at high pressure, the casting speed is high, and there is no stagnation in the middle, so that the filling is completed in a short time. Therefore, there is no generation of a solidified layer in the middle of the flow, and the gas is discharged in vacuum, so that there is little residual oxygen in the mold cavity 10, little oxide film is generated, and no molten gas is involved.

  In addition, an ambient gas passage 22a is provided on the entire outer periphery of the mold cavity 10 and communicates with the vacuum chamber 21 communicating with the vacuum suction mechanism. Outside air leaking from the mating surface of the mold is sucked by the vacuum suction mechanism. Is not absorbed into the mold cavity 10, and the pressure pin 20 communicating with the mold cavity 10 and the clearance around the extrusion pin are also communicated with the vacuum chamber 21. The outside air does not leak into the cavity 10 to cause a defect. This vacuum suction is performed until the molten metal in the mold cavity 10 is cooled and solidified, so that it is possible to more reliably prevent outside air from being mixed into the molten metal.

  After the molten metal inflow gate 11 is closed with the closing pin 13, the solidification shrinkage of the molten metal 8 occurs, so that the pressure plunger 14 and the pressure pin 20 are advanced to perform replenishment according to the solidification shrinkage volume. At this time, contact between the molten metal and the mold surface is maintained, and mixing of outside air is reliably prevented by vacuum suction. Replenishment according to the solidification shrinkage volume by the advancement of the pressure plunger 14 is difficult to transmit pressure to the end on the opposite side of the mold cavity 10, so pressurize by operating the pressure pin 20 around the end. Thus, a product having a dense structure free from shrinkage due to coagulation shrinkage can be obtained. Then, as shown in FIG. 7, after cooling and solidification of the molten metal in the mold cavity 10 is completed, the mold is opened, and the product material 28 lifted by the movable mold 2 is moved by the pressure pins and the extrusion pins. Extruded and removed.

  On the other hand, as shown in FIG. 5, after closing the molten metal inflow gate 11 with the closing pin 13, the gas pressure in the pouring pan 7 is immediately released to the atmosphere, and the lid 34 of the pouring pan 7 is opened to bring the pressure to no danger. In a lowered state, the pouring pan 7 is lowered to a slightly lower position by using a vertical movement device (not shown), outside air is introduced from the tip of the casting stalk 15, and the molten metal remaining in the casting stalk 15 is poured. 7 is dropped (FIG. 5). When the pouring pan 7 that has been lowered is cleaned with the horizontal movement device (not shown), the pouring stalk 15 is moved to a position where no foreign matter enters, and the molten metal necessary for the next time is supplied with the hot water supply ladle 29. Cover again and attach to the main body to prepare for the next casting.

  Further, as described above, even after the molten metal inflow gate 11 is closed with the closing pin 13, the gas pressure in the pouring pan 7 is released to the atmosphere, and the inside of the casting stalk 15 is kept at a vacuum pressure even when the pressure is reduced to a non-hazardous pressure. Since the molten metal does not fall into the pouring pan 7 until then, the molten metal in the molten metal inflow gate 11 and the cast stalk 15 is rarely cooled and a solidified layer is generated. In order to prevent this, the pouring pan 7 is lowered a little to create a gap at the tip of the casting stalk 15, allowing the outside air to flow in and the molten metal in the casting stalk 15 to drop immediately, and the inlet of the molten metal inflow gate 11. It is possible to prevent the solidified layer from occurring in the part and the cast stalk 15 and prevent the product from being mixed into the product. At that time, as shown in FIG. 11, when an inert gas is introduced instead of the outside air, oxidation of the molten metal surface 9 a in the cast stalk 15 can be prevented.

  Further, when the molten metal is filled in the mold cavity 10 by controlling the casting speed in order to prevent gas entrainment, the gas introduction means by the gas cylinder as shown in FIG. It is possible to accurately control the casting speed as shown.

  That is, in the casting stage of the molten metal, it is necessary to complete the filling of the mold cavity 10 within a short time when the molten metal 8 is not cooled and solidified, so that the molten metal 9a is pushed up quickly until it reaches the molten metal inflow gate 11, When the hot water passes through the molten metal inflow gate 11, the casting speed is reduced so that the molten metal does not leave the bottom surface around the molten metal inflow gate 11, and the hot water entrains the gas remaining in the upper part of the hub portion hot water reservoir 12. Do not. If the speed at this time is high, the molten metal 8 becomes a jet and is separated from the bottom surface around the molten metal inflow gate 11, and the tip of the molten metal collides with the ceiling of the hub portion hot water reservoir 12 to entrain gas. Further, after the molten metal 8 fills the hub reservoir 12, it reaches the molten metal inflow gate 11 without rapidly increasing the casting speed until the tip of the molten metal 8 is introduced into the gap for the pressurized plunger molten metal solidification zone. The speed is controlled to be equal to or lower than the previous maximum casting speed. As a result, the gas is discharged to the chamber through the pressurized plunger molten metal solidification zone gap and the pressurized plunger gas discharge gap, and the tip of the molten metal 8 is cooled and solidified by the pressurized plunger molten zone solidification zone. Thus, the flow is stopped, and the molten metal 8 does not enter the pressurized plunger gas discharge gap 18, thereby causing no trouble in the apparatus. On the other hand, when the casting speed is rapidly increased after the molten metal 8 has filled the hub portion hot water reservoir 12, the molten metal does not solidify in the pressure plunger molten metal solidification zone gap, and the narrow pressure plunger There is a case where it enters into the gas discharge gap, causing a trouble of the apparatus and hindering the operation.

That is, when the tip surface 9a of the molten metal 8 rises in the casting stalk 15, it is pushed in as quickly as possible, but when reaching the front of the molten metal inflow gate 11, the molten metal is decelerated to such an extent that it does not jump out due to inertia, When the molten metal inflow gate 11 is slowed down and the molten metal 8 is allowed to pass through the molten metal 8 at such a speed that the lower surface of the molten metal does not lift from the bottom surface around the molten metal inflow gate 11, Increase speed to reduce overall filling time and complete filling. When the filling is completed, it is effective for completely filling and preventing the formation of sink marks that the gas pressure in the gas pressurizing pouring pan 7 is 1 kg / cm ² or more and pressurizing the molten metal 8.

It is a schematic longitudinal cross-sectional view of the vertical casting apparatus of this invention, and is a figure which shows the state before casting. It is a figure at the time of integrating the obstruction | occlusion pin and pressurization stem of FIG. It is explanatory drawing which shows the working state of the vertical casting apparatus of this invention shown in FIG. 1, and shows the state with which the molten metal was filled in the mold cavity. It is explanatory drawing which shows the working state of the vertical casting apparatus of this invention shown in FIG. 1, and shows the state which filled the molten metal in the metal mold | die cavity and obstruct | occluded the inflow gate. It is explanatory drawing which shows the operation | working state of the vertical casting apparatus of this invention shown in FIG. 1, Comprising: Molten metal is filled in a mold cavity, an inflow gate is obstruct | occluded, casting stalk is pulled down a little, and the molten metal is dropped Show. It is explanatory drawing which shows the working state of the vertical casting apparatus of this invention shown in FIG. 1, and shows the state by which the molten metal in a mold cavity was pressurized. It is explanatory drawing which shows the working state of the vertical casting apparatus of this invention shown in FIG. 1, and shows the state which the cooling solidification of a molten metal is completed, a type | mold is opened, a product is taken out, and a casting stalk is heated. It is explanatory drawing which shows an example of the clamping cylinder of the vertical casting apparatus of this invention shown in FIG. It is explanatory drawing which shows the case where a gas cylinder is used for supply of the pressurized gas of the vertical casting apparatus of this invention shown in FIG. It is explanatory drawing which shows the change of the molten metal filling speed at the time of using the gas cylinder of FIG. It is explanatory drawing which shows the state in the case of introduce | transducing an inert gas between the states of FIG.4 and FIG.5, and preventing the oxidation of a hot_water | molten_metal surface.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Fixed metal mold 2 Movable metal mold 3 Fixed board 4 Movable board 5 Horizontal type 6 Movable metal mold holder 7 Pouring pot (gas pressurizing pouring pot)
7a Pan body 7b Hot water supply part 8 Molten metal 9 Hot water surface of hot water supply part 9a Hot water surface in cast stalk 10 Mold cavity 10a Mold cavity Hub part 10b Mold cavity Spoke part 10c Mold cavity Rim part 10d Overflow pool 11 Molten metal Inflow gate (circular gate)
12 Hub hot spring (cavity first hot water reservoir)
13 Blocking pin 14 Pressure plunger (Pressure stem)
15 Casting stalk 16 Pouring pan seal packing 17 Hydraulic cylinder for pressurizing plunger 18 Pressing plunger mounting yoke 19 Rim hot water reservoir 20 Rim pressurizing pin 21 Vacuum chamber 22 Gas passage 22a surrounding gas passage 23 Gas passage 24 Closure pin Hydraulic cylinder 25 Pressure pin mounting plate 26 Pressure pin hydraulic cylinder 27 Pressurized gas inlet 28 Product 29 Hot water supply ladle 30 Mold clamping cylinder (hydraulic cylinder)
31 Clamping piston 32 Lock gate 33 Rear platen 34 Pouring pan lid 35 Cast stalk heater 36 Gas cylinder for pouring gas pressurization 37 Driving screw 38 Driving pulse motor 39 Inert gas inlet 40 Inert gas

Claims (8)

Lower fixed mold and upper movable mold capable of forming mold cavities, closing means for closing the molten metal inflow gate formed in the fixed mold, and pressurizing the molten metal in the closed mold cavities An apparatus body having a pressurizing means;
Casting means equipped with a gas pressure pouring pan, supplying and filling molten metal from below into the mold cavity;
A vertical casting apparatus comprising:
The gas pressure injection Yunabe is one end of a long pan body in the horizontal direction, the hot water supply portion extending upwardly is provided, the other end of the pan body, the mold cavity mounted projecting upwardly Casting stalk that communicates is provided, the molten metal is present in the hot water supply part before and after casting , and the pressurized gas is not introduced into the pan body ,
The gas pressurization pouring pan and the apparatus main body can be attached and detached, and the sealing stalk is formed by inserting the tip of the casting stalk provided in the gas pressurization pouring pan into the molten metal inflow gate inlet of the fixed mold and attaching it to the apparatus main body. A vertical casting apparatus characterized by forming . 2. The vertical casting apparatus according to claim 1 , wherein the closing means for closing the molten metal inflow gate is formed integrally with the pressurizing stem, and has a small diameter portion for closing the molten metal inflow gate at the tip. Pressurization for controlling the pressurization speed of the molten metal by the pressurizing means so as to include a mold opening amount measuring means for measuring the mold opening amount of the fixed mold and the movable mold. vertical casting apparatus according to claim 1 or 2, further comprising a speed control means. The casting means includes a pressurized gas introducing means having a gas cylinder and a piston for introducing pressurized gas from the pressurized hot pot, and the filling speed in the mold cavity of the molten metal is controlled by controlling the piston speed. vertical casting apparatus according to any one of claims 1 to 3, characterized in that it is configured to control. The vertical casting apparatus according to any one of claims 1 to 4 , wherein the casting stalk includes heating means. Using the vertical casting apparatus according to any one of claims 1 to 5 , a molten metal is cast into a mold cavity through a casting stalk from a gas pressurized pouring pot, and after the molten metal fills the cavity, the fixed mold is used. A casting method in which the molten metal inflow gate formed is closed with a closing means, and then the molten metal in the mold cavity is pressurized with a pressure means,
Immediately after closing the molten metal inflow gate with the closing means, the gas pressure in the gas pressurized molten metal pan is released to the atmosphere and detached from the main body of the apparatus, and the next time the necessary molten metal is supplied to the gas pressurized molten metal hot pot, A vertical casting method characterized by being attached to a main body and preparing for the next casting. 7. The vertical casting method according to claim 6 , wherein the gas pressure in the gas pressurizing pouring pan is adjusted to 1 kg / cm ² or more and cast at a high speed in a short time. The vertical casting method according to claim 6 or 7 , wherein the casting is a light metal alloy thin and large casting.