JP2005040801A - Atmosphere adjustment type casting apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vacuum container which can easily adjust the atmosphere when casting the molten steel in a ladle into a mold, and in which it is unnecessary to exchange a shutoff seal for every casting without being in contact with air, an explosion prevention countermeasure is completed and the mold can be easily taken out. <P>SOLUTION: The atmosphere adjustment type casting apparatus comprises an airtight chamber comprising an exhaust pipe to exhaust gas inside, a plurality of introduction pipes to introduce inert gas inside, an air introduction pipe to introduce air inside, a pouring port to pour molten metal into a mold disposed inside, a truck capable of loading the mold on rails, and an opening part with the truck accessible thereto, an opening/closing door which is capable of opening/closing the opening part and airtight, and a communication pipe disposed in an abutting manner on a slide gate part to adjust the pouring amount of the molten metal in a ladle to pour molten metal in the mold. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a vacuum casting apparatus used for casting in various atmospheres such as atmospheric pressure, reduced pressure, and vacuum atmosphere gas.
[0002]
[Prior art]
As an example of the prior art, the technique described in JP-A-10-85920 is shown below. As shown in FIG. 6, the vacuum vessel 211 includes a vacuum chamber 213 and an upper lid 215. The vacuum chamber 213 is provided with a mold 221 inside, a vacuum suction exhaust pipe 217 for discharging the air inside the vacuum chamber 213 on the side wall, and air inside the vacuum chamber 213 when taking out a cast steel product. An air introduction valve 219 for injecting gas is provided, and the inside of the vacuum vessel 211 can be adjusted to a vacuum or an atmospheric state.
[0003]
A pouring port 225 for pouring molten steel 223 into the mold 221 is provided on the upper surface of the upper lid 215. On the upper lid 215, a ladle 227 containing molten steel 223 degassed in a vacuum degassing furnace is set. Then, the inside of the vacuum vessel 211 is evacuated by a vacuum pump (not shown) connected to the exhaust pipe 217, and casting is started. That is, the degassed molten steel 223 in the ladle 227 passes through the slide gate 237 and the pouring nozzle 239 inserted into the pouring port 225, and passes through the runner 231 from the pouring gate 233 of the mold 221. 229 is poured.
[0004]
Next, FIG. 7 which showed the detail of the pouring part 311 of FIG. 6 demonstrates. The pouring port 225 is provided with a pouring port flange 313 that protrudes upward, and a vacuum gasket 315 is disposed on the upper surface of the pouring port flange 313. Further, a cylindrical pouring nozzle 239 is disposed concentrically with the pouring port 225 so as to be pressed down by pressing the vacuum gasket 315 with the lower surface of the vacuum flange 317 provided projecting radially from the upper end. . At the upper end of the pouring nozzle 239, a vacuum shielding plate 321 is provided on the upper surface of the vacuum flange 317 via a shielding seal 319 so as to be closed except during pouring.
[0005]
The vacuum shielding plate 321 is made of a material that can withstand the vacuum pressure generated in the vacuum vessel 211 and instantly melts with the heat of the molten steel 223 when pouring is started. Specifically, an aluminum plate is effective. That is, until pouring is started, the pouring port 225 is completely sealed by the pouring nozzle 239 provided with the vacuum shielding plate 321 as shown in FIG. Can hold.
[0006]
When the middle plate 327 is slid rightward from the state before pouring shown in FIG. 7 so that the position of the hole 328 provided in the middle plate 327 matches the position of the hole formed in the upper nozzle 331, the lower plate 329 is obtained. The molten steel 223 in the ladle 227 flows to the lower end of the lower nozzle 333. Due to the inflow of the molten steel 223, the vacuum shielding plate 321 that has closed the upper end of the pouring nozzle 239 is instantaneously melted, and the molten steel is poured into the pouring gate 233 located below the pouring nozzle 239. The mold space 229 is filled through.
[0007]
Japanese Patent Laid-Open No. 7-148549 discloses another technical example. When molding a mold, the mold space is replaced with an inert gas such as nitrogen gas or argon gas, or the mold space of the mold is filled with an inert gas similar to the above before pouring after casting. After the replacement, pour hot water. Thus, since the inert atmosphere in the mold is continuously maintained, a technique for releasing the gas in the molten metal without generating an oxide film on the molten metal surface filled in the space in the mold is described. .
[0008]
[Patent Document 1]
Japanese Patent Laid-Open No. 7-148549
[Patent Document 2]
Japanese Patent Laid-Open No. 10-85920
[0009]
[Problems to be solved by the invention]
The problems of the prior art will be described below.
(1) About casting atmosphere adjustment
Usually, when casting, casting is performed by adjusting the atmosphere. The outline is as follows.
In general, when casting, there are three types of casting: casting under atmospheric pressure, under reduced pressure (eg 1.01 × 10 6 ⁴ Pa to 1.01 × 10 ³ Casting at Pa, under vacuum (eg 1.01 × 10 ³ Casting at Pa or less) is performed for each purpose. For this reason, there is a drawback that the same equipment cannot be used for different casting methods.
[0010]
Even in the case of casting under atmospheric pressure, argon gas or nitrogen gas is blown into the mold in order to prevent melt oxidation by the atmosphere during pouring. However, the effect of preventing oxidation was low due to air entrainment. Another object of the vacuum casting equipment described in the prior art is to pour molten degassed steel in the ladle into a sand mold without causing recontamination by the atmosphere during casting. However, there are various problems as described later.
[0011]
(2) About casting method to sand mold set in vacuum chamber
In the prior art, the upper opening of the pouring nozzle 239 is provided with a vacuum shielding plate 321 that is closed except during pouring via a shielding seal 319 on the upper surface of the vacuum flange 317, and this vacuum shielding. The plate 321 is made of a material that can withstand the vacuum pressure in the vacuum vessel 211 and instantly melts with the heat of the molten steel 223 at the start of pouring, specifically, an aluminum plate.
[0012]
However, according to the above prior art, first, the vacuum shielding plate 321 is consumed for each casting. For this reason, it is necessary to replace it every time it is cast. Secondly, when the contact surface between the vacuum vessel 211 and the ladle 227, for example, the contact surface between the vacuum flange 317 and the nozzle holder 335 shown in FIG. There was a possibility that air would enter due to a gap.
[0013]
(3) About chamber explosion prevention measures
When sand mold casting is performed by providing a mold in a vacuum vessel, it is necessary to remove from the sand mold after casting. For this purpose, the inside of the vacuum vessel must be returned to atmospheric pressure. However, there is a possibility that the flammable gas generated from the sand mold is filled in the vacuum container. Therefore, it is conceivable that combustible gas in the chamber explodes when air is mixed.
[0014]
(4) Vacuum container shape
In the conventional example, the vacuum vessel 211 has a vertical structure including an upper lid 215 that closes the upper opening. Therefore, when the mold 221 is set in the vertical structure vacuum container 211, it is necessary to open and close the upper lid 215 and lift and move the mold 221 with a crane or the like. For this reason, a great deal of labor is required for setup and preparation.
[0015]
Therefore, the present invention makes it easy to adjust the casting atmosphere when casting the molten steel in the ladle into the mold, and does not need to be in contact with the atmosphere, and it is not necessary to replace the shut-off seal for each casting, so that the sealing is sufficient. There is a need to provide a vacuum vessel that is complete with explosion-proof measures and can be easily taken out of a mold.
[0016]
[Means for Solving the Problems]
In order to solve the above problems, the following invention is provided.
According to a first aspect of the present invention, there is provided an atmosphere adjustment type casting apparatus having the following structure.
(A) An exhaust pipe (9) for exhausting internal gas, a plurality of introduction pipes (11, 13) for introducing an inert gas therein, and an air introduction pipe (15 for introducing air into the interior) ), A pouring port (28) for pouring the molten metal into the mold (7) disposed inside, a carriage (17) on which the mold can be placed on the rail, and the carriage can be taken in and out. An air-tight chamber (3) with an opening (29);
(B) an open / close door (5) capable of opening and closing the opening (29) and capable of being kept airtight;
(C) a communication pipe (27) provided so as to abut on a slide gate part (25) for adjusting the pouring amount of the molten metal (23) of the ladle (21) poured into the mold (7);
Is provided.
[0017]
According to a second aspect of the present invention, the communication pipe (27) includes a cushion member (91) provided so as to be extendable and contracted so that no gap is generated when contacting the slide gate portion of the ladle. The atmosphere adjusting type casting apparatus according to claim 1, further comprising a seal hardware (101) for preventing air from entering the chamber during vacuum suction.
[0018]
According to a third aspect of the present invention, the communication pipe (27) is made of a refractory and cylindrical sleeve brick (73, 74) for passing molten metal,
In order to protect the sleeve bricks (73, 74), a flange (77) having a heat-resistant seal (75) disposed on the upper surface is provided outside the upper end, and the lower end is used to support the sleeve brick inserted inside. A heat-resistant cylindrical tube (81) with a flange (79) of
A cylindrical cylindrical portion having a flange (77) having a heat-resistant seal (75) disposed at the upper end and a flange (87) having a heat-resistant seal (85) disposed on the lower surface at the lower end ( 83)
An upper end is fixed to a flange (89) provided to abut on a flange (87) provided at the lower end of the cylindrical portion (83), and a lower end is fixed to a flange (93) provided at the lower end. A bellows-like cushion member (91);
A flange (97) provided so as to abut on a flange (93) provided at the lower end of the cushion member (91), a heat-resistant seal (95) disposed on the upper surface, and fixed to the beam (99) When,
A seal hardware (101) for contacting the lower surface of the flange (79) provided to support the sleeve bricks (73, 74) provided in the cylindrical shape to keep the gas tight so as not to leak. It is an atmosphere adjustment type | mold casting apparatus characterized by having.
[0019]
According to a fourth aspect of the present invention, the seal hardware (101) is provided in a circumferential direction on the bottom surface of the flange (79) provided to support the sleeve bricks (73, 74). A heat-resistant seal (105) is provided on the upper surface of the flange, and a concave recess having the same opening dimension is formed in the diameter of the opening of the flange (79) provided to support the sleeve brick (73, 74). And an atmosphere adjustment type casting apparatus which is provided so as to be movable up and down and left and right by a driving device (107).
[0020]
According to a fifth aspect of the present invention, there is provided an atmosphere adjustment type casting apparatus, wherein the mold (7) is a sand mold.
[0021]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below. FIG. 1 is a cross-sectional view showing an atmosphere adjustment type casting facility 1 of the present embodiment. An exhaust pipe 9 for vacuum suction for exhausting gas (including air) inside the chamber 3 and an argon gas introduction pipe for introducing an inert gas into the chamber 3 in the chamber 3 of the atmosphere-controlled casting equipment 1 11. A nitrogen gas introduction pipe 13 and an air introduction pipe 15 for introducing air into the chamber 3 to return to atmospheric pressure when taking out a cast steel product are provided.
[0022]
After casting, nitrogen gas and air can be introduced at the same time to quickly return to atmospheric pressure avoiding the explosive limit of combustible gas generated by thermal decomposition of organic compounds such as resins used for mold production.
[0023]
In the upper part of the chamber 3, a pouring port 28 for pouring the molten metal into the mold 7 disposed in the chamber 3 is provided.
[0024]
A mold 7 is installed in the chamber 3. The mold 7 in the chamber 3 is placed on a carriage 17. The carriage 17 is movably disposed on a rail 19 provided at the bottom of the chamber 3, and can move on a rail 20 provided outside the chamber 3 when the opening / closing door 5 is opened.
[0025]
At the time of casting, for example, a ladle 21 holding the molten metal 23 is disposed on the chamber 3, and the molten metal is poured into the mold 7 through the pouring port 28 by opening and closing the slide gate portion 25 provided at the bottom of the ladle 21. . The pouring gate 28 has a sealing function for preventing air from entering the chamber 3 when vacuuming the chamber 3, and there is no gap when connected to the slide gate portion 25 of the ladle 21. Thus, a communication pipe 27 having a cushion function is provided.
[0026]
FIG. 2 shows a cross-sectional view of the chamber of this embodiment. FIG. 2A is a cross-sectional view of the chamber 3, and FIG. 2B is a plan view of the chamber 3. The chamber 3 is a chamber whose outer shape is long in the horizontal direction and has a substantially oval cross section. In order to reinforce the chamber 3 and to support the weight of the ladle 21 holding the molten metal 23, a rectangular steel pipe 31 is provided. It has a structure that is reinforced by use, and is lightweight and highly rigid.
[0027]
A mold 7 is installed in the chamber 3, and the mold 7 is placed on, for example, an electric carriage 17. The carriage 17 is movable on a rail 19 in the chamber 3 and a rail 20 provided outside the chamber 3 to be connected.
[0028]
An explosion-proof valve 35 is provided on the upper portion of the chamber 3. The explosion-proof valve is provided in order to escape an increase in the internal pressure of the chamber due to an explosion of a combustible gas generated by thermal decomposition of an organic compound such as a resin used for manufacturing a mold during casting or the like. Note that a measuring device for detecting the flammable gas concentration in the chamber may be attached to the chamber.
[0029]
In addition, an opening 35 of a pouring port 28 for pouring the molten metal 23 into the mold 7 in the chamber 3 is provided in the upper part of the chamber 3. A communication pipe 27 is provided in the opening 35.
[0030]
An opening / closing door 5 is provided in the opening 29 of the chamber 3 shown in FIG. Here, the open / close door 5 is provided so as to be vertically slidable along a guide rail (not shown), and the open / close door 6 indicates a partially opened state. In this way, by making the door open by sliding the door upward, the dead space can be reduced as compared with the side opening door.
[0031]
The open / close door 5 has a function of closing with a driving device such as a motor when the mold is carried into the chamber 3. Further, it is locked so as not to be opened until a predetermined vacuum is reached, and has a function of releasing the lock while maintaining a hermetic seal when the predetermined vacuum is reached. Therefore, in the unlikely event that the internal pressure increases due to an explosion or the like in the chamber 3, the door is opened upward, so that safety is high.
[0032]
In FIG. 3, it showed about the cross-sectional schematic of the ladle concerning this embodiment. The slide gate part 25 provided in the bottom part of the ladle 21 is demonstrated. The slide gate unit 25 includes an upper nozzle 51, an upper plate 53, an intermediate plate 55, a lower plate 57, a lower nozzle 59, and a nozzle cover 61 that fixes the nozzle.
[0033]
Here, the upper plate 53 is fixed to the lower surface of the upper nozzle 51 and has a hole concentric with the upper nozzle 51. The middle plate 55 is slidable between the lower plate 57 and the upper plate 53 to adjust the amount of hot water during casting, and the upper nozzle 51 and the lower nozzle 59 communicate with each other so as to coincide with the holes of the upper nozzle 51 and the lower nozzle 59. Holes are provided. The lower plate 57 is provided with a hole concentric with the lower nozzle 59. The lower nozzle 59 is disposed concentrically with the upper nozzle 51 by providing a lower nozzle cover 61 on the outer periphery.
[0034]
FIG. 4 shows a detailed cross-sectional view of the communication pipe of the present embodiment. The ladle 21 is placed on a ladle cradle 68 through a ladle bottom plate 67 and legs 69. A bottom plate 57, a lower nozzle 59, and a lower nozzle cover 61 are shown connected to the slide gate 25 at the bottom of the ladle 21. At the lower end of the lower nozzle cover 61, for example, a flange 71 fixed by welding or the like is provided.
[0035]
The communication pipe 27 will be described below. First, sleeve bricks 73 and 74 made of a refractory and provided in a cylindrical shape and sleeve bricks 73 and 74 are used for the communication pipe 27, and a heat-resistant seal 75 is provided at the upper end. For example, a flange 77 fixed by welding or the like is provided. A heat-resistant cylindrical tube 81 having a flange 79 fixed by welding or the like is provided at the lower end to support the sleeve bricks 73 and 74 inserted inside.
[0036]
A flange having a heat resistant seal 75 disposed on the upper surface of the flange 77 and a cylindrical portion 83 are connected to the flange, and fixed to a flange 87 having a heat resistant seal 85 below the flange.
[0037]
A flange 89 is fixed to the lower side of the flange 87 by bolting or the like. An upper end of a bellows-like cushion member 91 made of a heat-resistant material is fixed to the flange 89 by, for example, welding. The lower end of the cushion member 91 is fixed to the flange 93 by welding or the like.
[0038]
Below the flange 93, there is a flange 97 having a heat resistant seal 95 disposed on the upper surface. The flange 97 is fixed to the beam 99 by welding or the like.
[0039]
The seal hardware 101 includes a flange 79 provided to support the sleeve bricks 73 and 74 provided in a cylindrical shape, abuts against the bottom surface of the flange 79, and gas (including air) through the sleeve bricks 73 and 74 and the like. Has a function to keep airtight so as not to leak. For this reason, the seal hardware 101 is provided with a heat-resistant seal 105 on the upper surface of the seal metal 101 in the circumferential direction of the bottom surface of the flange 79 so as to be in contact with the bottom surface of the flange 79 and to be kept airtight.
[0040]
A concave recess 103 having an opening size substantially the same as the diameter of the opening of the flange 79 is formed on the upper surface of the seal hardware 101. The seal hardware 101 is movable up and down and left and right by a drive device 107 installed on the beam 99 and operated by, for example, an air cylinder.
[0041]
That is, as shown in FIG. 4, the space between the flange 79 and the metal seal 101 is closed during vacuum suction. However, when a predetermined degree of vacuum is reached and the molten metal is injected, the driving device 107 disposes the metal seal 101. Lowering and then rotating to the left or right does not hinder pouring of the melt. If the operation is reversed, it can be sealed again. Moreover, it cannot be overemphasized that it can be used repeatedly.
[0042]
Therefore, when the ladle 21 is set at a predetermined position on the chamber, the flange 71 provided on the lower nozzle cover 61 of the slide gate portion 25 and the flange 77 provided on the upper end of the cylindrical portion 83 come into contact with each other. Then, due to the weight of the ladle or the like, the flange 77 descends, and at the same time, the cushion member 91 is pushed and contracted, so that the lower nozzle 59 and the sleeve brick 73 are in contact with each other with a heat-resistant sealing material not shown.
[0043]
Since the cushion member 91 has elasticity, a force to push up from the flange 89 acts. Therefore, even when the position of the flange 71 is slightly shifted or inclined, the flange 71 and the heat-resistant seal 75 disposed on the flange 77 are in close contact with each other, and there is no gap between the flange 71 and the flange 77. Airtightness is maintained.
[0044]
Therefore, it is necessary to select the descending dimension of the flange 77 and the material of the cushion member 91 so as not to apply an excessive load to the lower nozzle 59 and the sleeve brick 73. The cushion member 91 has a bellows shape, a wave shape, or the like, and any shape and material can be used as long as it has the above function. For example, although the dimension which the cushion member 91 shrinks depends on design conditions, it can be selected from about 10 to 29 mm, desirably about 20 to 30 mm.
[0045]
In the present embodiment, although not shown, a vacuum facility is provided that is connected to an exhaust pipe and rapidly exhausts gas (including air) inside the chamber. For example, a vacuum device such as a water ring pump or a mechanical pump can be used so that a degree of vacuum of about 100 Pa can be obtained.
[0046]
Next, the casting method of this embodiment is demonstrated using FIGS. First, the mold 7 is cast sand, for example, and a molten metal 23 is poured to form a mold space 131 in which a cast steel product is formed. Here, the mold space 131 is communicated with a sprue 133 provided below the runner 133, the feeder part 135, and the pouring gate 28. Thus, the prepared mold 7 is placed on the carriage 17, moves on the rail 20, passes through the opening 29 of the open / close door 5, and is set at a predetermined position in the chamber 3. The open / close door 5 provided in the chamber 3 is closed and locked.
[0047]
Next, the seal hardware 101 is brought into contact with the bottom of the communication pipe 27 so that the sealed state is maintained. A ladle 21 holding a molten metal 23 is set on the chamber 3. When the ladle 21 is set, the slide gate 25 at the bottom of the ladle and the communication pipe 27 are connected.
[0048]
Next, the inside of the chamber 3 is evacuated by a vacuum device communicating with the exhaust pipe 9. After the evacuation, the lock of the open / close door 5 (not shown) is released. However, the vacuum is evacuated and the inside of the chamber 3 has a negative pressure, and no gap is generated between the open / close door 5 and the chamber 3. An inert gas may be introduced into the chamber 3 before evacuation. When casting in vacuum, suction is performed with a vacuum pump until a predetermined vacuum is reached.
[0049]
In addition, the atmosphere in the chamber 3 is not limited to a predetermined degree of vacuum, and the atmosphere in the chamber 3 is replaced with an inert gas, and casting in an inert gas atmosphere is possible. Accordingly, the atmosphere (air) can be changed to a nitrogen atmosphere or an argon atmosphere in a short time, and a desired reduced pressure state or vacuum state can be obtained in a short time with a vacuum apparatus (pump). That is, it is possible to perform casting under various conditions using one facility.
[0050]
Next, pouring is started. First, the metal seal 101 that has been in contact with the bottom of the communication pipe 27 is removed, and the middle plate 55 of the slide gate 25 provided at the bottom of the ladle 21 is shifted to pour the molten metal 23.
[0051]
The molten metal 23 that has passed through the sleeve bricks 73 and 74 reaches the mold space 131 from the gate 137 of the mold 7 through the runner 133. When the molten metal 23 is poured, the member used for the mold 7 is burned by the heat of the molten metal 23 to generate gas. This gas diffuses into the chamber 3 and is discharged to the outside through the exhaust pipe 9.
[0052]
After pouring is completed, the middle plate 55 of the slide gate portion 25 provided at the bottom of the ladle 21 is shifted and closed, and the seal hardware 101 is brought into contact with the bottom of the communication pipe 27. Before opening the opening / closing door 5 and taking out the mold 7 from the chamber 3, it is necessary to introduce air into the chamber 3 to return to atmospheric pressure. At this time, in order to prevent the combustible gas generated by burning the member used for the mold 3 in the chamber and the air from mixing and reaching the explosion limit, air is supplied from the air introduction pipe 15 and nitrogen gas is supplied from the nitrogen. It introduce | transduces from the gas introduction pipe | tube 13, and air is diluted and the inside of the chamber 3 is returned to atmospheric pressure.
[0053]
After the inside of the chamber 3 becomes atmospheric pressure, the opening / closing door 5 is opened, and the carriage 17 on which the mold 7 is placed moves on the rail 19 and passes through the opening 29 of the opening / closing door 5 to the outside of the chamber 3. It is taken out.
[0054]
When casting is performed using the atmosphere-controlled casting equipment of this embodiment, there is no air entrainment during casting. In addition, since a gas generated by thermal decomposition of a member used for forming the mold, for example, resin is instantaneously diffused, a cast product having no gas defects can be obtained. Furthermore, since there is no air resistance or gas resistance in the mold, the molten metal flows to the tip of the thin cast product, and no oxide film is generated, so that it is possible to manufacture a thin cast product that is difficult to manufacture.
[0055]
That is, when the atmosphere adjustment type casting equipment of this embodiment is used, the atmosphere (air) can be changed to a nitrogen atmosphere or an argon atmosphere in a short time, and a desired reduced pressure state or vacuum state can be obtained in a short time. it can. That is, it is possible to perform casting under various conditions using one facility. Furthermore, not only the melt that has been subjected to the vacuum degassing treatment that is normally performed but also the melt that has not been subjected to the vacuum degassing treatment can be cast without entrainment of air.
[0056]
Therefore, when using the atmosphere adjustment type casting equipment of this embodiment, it is possible to cast large / thin products and large / light products that cannot be produced by the conventional lost wax method. Conventionally, casting is impossible or extremely difficult. Low carbon steel materials can now be cast in sand molds. For example, low-carbon stainless steel castings, nickel-base alloy castings (eg JIS H 5701), pure iron, 42% Ni cast steel, special magnetic materials such as 60% Ni cast steel, heat-resistant cast steel products such as high nickel / high cobalt, iron It is possible to cast low thermal expansion alloy, high damping cast steel, low yield spot cast steel, etc.
[0057]
【Example】
(Example)
Next, an example explains the present invention. First, a mold having a predetermined shape was prepared using alkali phenol sand. The mold was placed on an electric carriage using a crane, moved on the rail, passed through the opening of the open door, and set at a predetermined position in the chamber. The door provided in the chamber was closed and locked. Next, the chamber was evacuated with a vacuum pump.
[0058]
Next, a ladle holding a molten steel melted so that the component composition (mass%) was an alloy of 13% Cr—Fe was set on the chamber 3. When the ladle was set, the slide gate portion at the bottom of the ladle and the communication pipe were connected, and the seal hardware driven by the air cylinder was brought into contact with the bottom of the communication pipe.
[0059]
Since the degree of vacuum reached a predetermined 100 Pa, the metal seal that had been in contact with the bottom of the communication pipe was removed, and the middle plate of the slide gate provided at the bottom of the ladle was shifted to start pouring molten steel. During pouring, argon gas was blown through the slide gate. At the end of pouring, the middle plate of the slide gate portion was shifted and closed, and the seal hardware was brought into contact with the bottom of the communication pipe.
[0060]
Before opening the door and removing the mold from the chamber 3, the pressure was returned to atmospheric pressure while introducing a mixed gas of air and nitrogen gas so as not to reach the explosion limit. After the inside of the chamber became atmospheric pressure, the door was opened, and the carriage on which the mold was placed moved on the rail, passed through the open door, and was taken out of the chamber. Next, the cast product was taken out from the mold and subjected to normal post-processing to produce a trial product of the honeycomb-shaped product shown in FIG.
[0061]
The dimensions of the honeycomb-shaped product are 1000 mm in length, 1000 mm in width, and 200 mm in height. When repeatedly cast using this atmosphere-controlled casting equipment, the cast product is thin and has no casting defects. was gotten. That is, the hot water sufficiently passed around the thin-walled portion, and oxidation by air did not occur.
[0062]
(Comparative example)
A cast product was manufactured using the conventional technique. The component composition is the same as in the examples. The dimensions were 290 mm in length, 290 mm in width, 200 mm in height, and 4 mm in thickness. Further, when casting was performed with the dimensions of 1000 mm in length, 1000 mm in width, and 200 mm in height, the thickness was 5 mm. When the wall thickness was made thinner than this, casting defects such as hot water wrinkles and hot water boundary casting defects occurred.
[0063]
【The invention's effect】
The atmosphere adjustment type casting equipment of the present invention is easy to adjust the casting atmosphere at the time of casting into the mold, is sufficiently sealed and does not come into contact with the atmosphere, and it is necessary to replace the shut-off seal at every casting. Absent. Further, the gas generated from the mold during pouring is diffused and exhausted into the chamber, and the explosion-proof measures are complete during and after casting, and the mold can be easily taken out. Accordingly, a thin cast product free from casting defects can be obtained.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing an atmosphere adjustment type casting facility according to an embodiment of the present invention.
FIG. 2 is a cross-sectional view of a chamber according to an embodiment of the present invention.
FIG. 3 is a cross-sectional view of a ladle according to an embodiment of the present invention.
FIG. 4 is a cross-sectional view of the communication pipe of the present invention.
FIG. 5 is a honeycomb-shaped product of the present example.
FIG. 6 is a cross-sectional view of a conventional vacuum casting apparatus.
FIG. 7 is a partial cross-sectional view showing details of a pouring part shown in FIG. 6 of a conventional example.
[Explanation of symbols]
1 Atmosphere control type casting equipment
3 Chamber
5 Opening door
7 Mold
9 Exhaust pipe
11 Argon gas inlet tube
13 Nitrogen gas introduction pipe
15 Air inlet pipe
17 bogie
19 rails
20 rails
21 Ladle
23 Molten metal
25 Slide gate
27 Communication pipe
28 Pouring gate
29 opening
31 square steel pipe
33 opening
35 Explosion-proof valve
51 Upper nozzle
53 Upper plate
55 Medium plate
57 Lower plate
59 Lower nozzle
61 Lower nozzle cover
63 Gas blow plug
65 Gas pipe
67 Ladle bottom plate
68 Ladle holder
69 legs
71 Flange
73 Sleeve brick
74 Sleeve brick
75 seal
77 Flange
79 Flange
81 Cylindrical tube
83 Cylindrical part
85 seal
87 Flange
89 Flange
91 Cushion material
93 Flange
95 seal
97 flange
99 Liang
101 Seal hardware
103 depression
105 seal
107 Drive device
131 Mold space
133 Yudo
135 Hot water club
137
211 vacuum vessel
213 vacuum chamber
215 Top lid
217 Exhaust pipe
219 Air introduction valve
221 mold
223 Molten steel
225 pouring gate
227 Ladle
229 Mold space
231 Yudo
233
235 feeder
237 slide gate
239 Pouring nozzle
311 pouring part
313 Pouring flange
315 Vacuum gasket
317 Vacuum flange
319 Blocking seal
321 Vacuum shield
323 Fireproof seal
325 Upper plate
327 Medium plate
328 holes
329 Lower plate
331 Upper nozzle
333 Lower nozzle
335 Nozzle holder

Claims (5)

An atmosphere adjustment type casting apparatus having the following structure. (A) An exhaust pipe (9) for exhausting internal gas, a plurality of introduction pipes (11, 13) for introducing an inert gas therein, and an air introduction pipe (15 for introducing air into the interior) ), A pouring port (28) for pouring the molten metal into the mold (7) disposed inside, a carriage (17) on which the mold can be placed on the rail, and the carriage can be taken in and out. An air-tight chamber (3) with an opening (29);
(B) an open / close door (5) capable of opening and closing the opening (29) and capable of being kept airtight;
(C) a communication pipe (27) provided so as to abut on a slide gate part (25) for adjusting the pouring amount of the molten metal (23) of the ladle (21) poured into the mold (7);
Is provided. The communication pipe (27) is a cushion member (91) provided so as to be able to expand and contract so as not to generate a gap when abutting with the slide gate portion of the ladle. The atmosphere adjusting type casting apparatus according to claim 1, further comprising a seal hardware (101) for preventing intrusion of the atmosphere. The communication pipe (27) is made of a refractory and cylindrical sleeve brick (73, 74) for passing molten metal,
In order to protect the sleeve bricks (73, 74), a flange (77) having a heat-resistant seal (75) disposed on the upper surface is provided outside the upper end, and the lower end is used to support the sleeve brick inserted inside. A heat-resistant cylindrical tube (81) with a flange (79) of
A cylindrical cylindrical portion having a flange (77) having a heat-resistant seal (75) disposed at the upper end and a flange (87) having a heat-resistant seal (85) disposed on the lower surface at the lower end ( 83)
An upper end is fixed to a flange (89) provided to abut on a flange (87) provided at the lower end of the cylindrical portion (83), and a lower end is fixed to a flange (93) provided at the lower end. A bellows-like cushion member (91);
A flange (97) provided so as to abut on a flange (93) provided at the lower end of the cushion member (91), a heat-resistant seal (95) disposed on the upper surface, and fixed to the beam (99) When,
A seal hardware (101) for contacting the lower surface of the flange (79) provided to support the sleeve bricks (73, 74) provided in the cylindrical shape to keep the gas tight so as not to leak. The atmosphere control type casting apparatus according to claim 1, wherein the atmosphere adjustment type casting apparatus is provided. The seal hardware (101) is formed on the upper surface of the seal hardware (101) in the circumferential direction of the bottom surface of the flange (79) provided to support the sleeve bricks (73, 74). ), And a concave recess having the same opening dimension is formed in the diameter of the opening of the flange (79) provided to support the sleeve brick (73, 74). And the atmosphere adjustment type | mold casting apparatus in any one of Claims 1-3 movably provided in right and left. The atmosphere adjusting type casting apparatus according to any one of claims 1 to 4, wherein the mold (7) is a sand mold.

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