JP2020146739A - Casting apparatus and casting method - Google Patents

Abstract

To provide a casting apparatus which can shorten a time required for filling molten metal into a cavity.SOLUTION: A casting apparatus 1 reduces a pressure in a casting cavity 42 and a sprue 47 by a pressure reduction mechanism 50 in the state that the sprue 47 is blocked by a center pin 49, and applies a pressurizing force to the molten metal M with a gas by a gas pressure application mechanism, and then, moves the center pin 49 to an open position and maintains the center pin 49 at the open position, and thereafter, advances the center pin 49 to a blocking position, and releases pressurization by the gas pressure application mechanism and pressure reduction by the pressure reduction mechanism in order.SELECTED DRAWING: Figure 2

Description

The present invention relates to a casting apparatus and a casting method for manufacturing a product by filling a mold with a molten metal in which a metal material is melted.

Conventionally, for example, Patent Document 1 is known as a vertical casting apparatus for manufacturing an aluminum composite product such as an aluminum wheel or an engine block by a low-pressure casting method or a low-medium-pressure casting method.
The vertical casting apparatus of Patent Document 1 includes a lower fixed mold and an upper movable mold capable of forming a cavity having a gas discharge passage, and a vacuum for supplying and filling the molten metal into the cavity from below. It is provided with a suction means. Further, in the vertical casting apparatus of Patent Document 1, after the molten metal cast in the cavity fills the inside of the cavity, a closing pin for closing the molten metal inflow gate provided in the fixed mold and a closed mold cavity are provided. It is equipped with a pressurizing stem that pressurizes the molten metal inside.
The vertical casting apparatus of Patent Document 1 reduces the pressure by vacuum suctioning the inside of the cavity after the mold clamping is completed, and sucks up the molten metal. As a result, the molten metal is filled in the cavity. When the flow of molten metal in the cavity is stopped, the flow of suction gas is also stopped, and the gate of the mold cavity is immediately closed with the closing pin. As a result, after the molten metal in the cavity is closed so as not to flow back, the pressure stem is immediately advanced to pressurize, and the molten metal in the semi-solidified state is replenished and filled in the cavity.

JP-A-2007-253234

In Patent Document 1, the cavity is depressurized by vacuum suction to fill the molten metal. However, it cannot be said that the rate of filling the cavity with the molten metal due to the decompression of the cavity is high, and therefore the temperature of the molten metal drops while the molten metal is filled in the cavity. Then, since the solidified layer is formed before the filling is completed, there is a possibility that a hot water boundary or a hot water wrinkle may occur when the gate is closed by the closing pin.
Therefore, an object of the present invention is to provide a casting apparatus and a casting method capable of shortening the time for filling the molten metal into the cavity.

The casting apparatus of the present invention includes a casting mold having a casting cavity in which molten metal is filled through a sprue, a closed body that reciprocates between a closed position for closing the sprue and an open position for opening the sprue, and a molten metal. A pouring chamber in which water is stored, a gas pressure applying mechanism that applies a pressure by gas to raise the molten metal level stored in the pouring chamber, and a depressurizing mechanism that depressurizes the casting cavity and sprue. Be prepared.
In the casting apparatus of the present invention, in a state where the sprue is closed by the closed body at the closed position, the casting cavity and the sprue are depressurized by the decompression mechanism, and the molten metal is pressurized by gas by the gas pressure applying mechanism. The closed body is moved to the open position, the closed body is maintained in the open position, and then the closed body is advanced to the closed position, and the pressing force is released by the gas pressure applying mechanism and the depressurized body is released by the depressurizing mechanism in order. Do.

In the casting apparatus of the present invention, preferably, after the closed body advances to the closed position, a metal pressure is applied to the molten metal in the casting cavity to replenish the solidification shrinkage of the molten metal, and then the depressurization is released.
The decompression mechanism in the present invention preferably includes a decompression chamber behind the obstructed body, and decompression is performed through the decompression chamber.

The decompression mechanism in the present invention preferably includes a first vacuum tank, a cavity suction pipe connected to the first vacuum tank and communicated with the casting cavity, a second vacuum tank independent of the first vacuum tank, and a second vacuum tank. It is provided with a vacuum chamber suction pipe which is connected to and communicates with the vacuum chamber. In this decompression mechanism, preferably, decompression from the decompression chamber suction pipe through the decompression chamber is performed in advance, and then decompression of the cast cavity from the cavity suction pipe is performed.
In the present invention, preferably, the sprue is closed by the closed body, and the pressure is reduced and the pressure is applied to move the closed body to the open position after the molten metal comes into contact with the closed body.

The present invention also provides a casting method in which the molten metal stored in the pouring chamber is filled into the casting cavity through the sprue.
The present invention includes a first step, a second step and a third step.
In the first step, the casting cavity, the sprue, and the space below the sprue are depressurized while the sprue is closed, and a pressing force is applied to the surface of the molten metal by gas.
In the second step, the casting cavity is filled with the molten metal by releasing the blockage of the sprue while applying the reduced pressure and the pressing force.
In the third step, the sprue is closed and the pressing and depressurizing are released in order.

In the third step of the present invention, the depressurization is preferably released after the solidification shrinkage of the molten metal in the casting cavity is replenished.

According to the casting apparatus of the present invention, before filling the casting cavity with the molten metal, the sprue is closed by the closing body, the casting cavity and the sprue are depressurized, and the molten metal level is raised by the pressure of gas. After that, the obstructed body is moved to the open position. This allows for rapid filling of the molten metal into the casting cavity. Therefore, according to the casting apparatus of the present invention, the molten metal can be filled in a state where the temperature drop is small, and the propagation range of the pressing force by the closed body is uniformly widened, so that a high quality cast product can be obtained. ..

It is sectional drawing which shows the schematic structure of the casting apparatus which concerns on embodiment of this invention. The process of casting using the casting apparatus of FIG. 1 is shown, (a) is blocking the sprue with a closing pin, (b) is sucking the cavity under reduced pressure, and (c) is the molten metal in the pressurizing chamber. A pressing force by gas is applied to the surface of the molten metal. The process of casting using the casting apparatus of FIG. 1 is shown, (a) retreating the closing pin to open the sprue, (b) advancing the closing pin to close the sprue, and (c) further closing the sprue. The obstruction pin is advanced to apply metal pressure to the molten metal in the cavity. It is a flowchart which shows the casting procedure performed by using the casting apparatus of FIG.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
As shown in FIG. 1, the casting apparatus 1 according to the present embodiment includes a holding chamber 10 for holding the molten metal M, a pressurizing chamber 20 for accommodating and pressurizing the molten metal M supplied from the holding chamber 10, and a casting die. A pouring chamber 30 which is arranged below the mold 40 and accommodates the molten metal M supplied from the pressurizing chamber 20 is provided. The molten metal stored in the pouring chamber 30 is filled with gas pressurization toward the casting die 40.

The casting device 1 is a depressurizing mechanism that vacuum-sucks a casting die 40 for casting the molten metal M supplied through the holding chamber 10, the pressurizing chamber 20, and the pouring chamber 30 in this order, and the casting cavity 42 of the casting die 40. 50 and.
The casting apparatus 1 fills the casting cavity 42 with the timing of closing the sprue 47 by the center pin 49 as a closing body included in the casting die 40, depressurizing the casting cavity 42 by vacuum suction, and pressurizing the molten metal M. The molten metal M is quickly filled. The casting device 1 includes a controller 70 that controls these operations.

[Holding chamber 10, pressurizing chamber 20 and pouring chamber 30]
Since the holding chamber 10 has a side wall which is not shown in FIG. 1 which is a cross-sectional view, the holding chamber 10 has a space surrounded by a periphery. As shown in FIG. 1, the holding chamber 10 includes a partition 11 forming a boundary with the pressurizing chamber 20, a molten metal passage 13 connected to the pressurizing chamber 20, and a bottom wall 15 separating the molten metal passage 13 and the holding chamber 10. , Equipped with.

The bottom wall 15 is provided with an on-off valve 17 that controls the supply of the molten metal M from the holding chamber 10 to the pressurizing chamber 20. The on-off valve 17 includes a through hole 17A formed in the bottom wall 15, a valve body 17B that advances and retreats through the through hole 17A, a support shaft 17C that supports the valve body 17B, and a cylinder that is a drive source for raising and lowering the support shaft 17C. It is equipped with 17D.
The opening and closing of the valve body 17B is controlled based on the instruction of the controller 70 so that a constant amount of molten metal M is always contained in the pressurizing chamber 20 in, for example, in the initial state of the casting process by the casting apparatus 1.

The upper end openings of the holding chamber 10 and the pressurizing chamber 20 are closed by the lid 14. In each of the holding chamber 10 and the pressurizing chamber 20, there is a closed space between the lid 14 and the molten metal M.
The support shaft 17C penetrates the lid 14 corresponding to the holding chamber 10, and the cylinder 17D is mounted on the lid 14. Further, the lid 14 corresponding to the holding chamber 10 is provided with a supply port 16 for supplying the molten metal M to the holding chamber 10.

[Decompression mechanism]
Further, the lid 14 corresponding to the pressurizing chamber 20 is provided with a gas supply path 21.
The gas supply path 21 is connected to the gas supply source 22. For example, an inert gas in a pressurized state is stored in the gas supply source 22, and the inert gas is supplied to the pressurizing chamber 20 through the gas supply path 21 and the molten metal M of the pressurized chamber 20 has a molten metal surface MS. Press to apply pressure. The pressing force by the gas through the gas supply path 21 is applied according to the instruction of the controller 70.
The pressurizing chamber 20, the gas supply path 21, and the gas supply source 22 constitute the gas pressure applying mechanism in the present invention.

The lid 14 corresponding to the pressurizing chamber 20 is provided with a molten metal level detecting rod 23 extending toward the molten metal surface of the molten metal M in the pressurizing chamber 20. The molten metal level detecting rod 23 detects whether or not the molten metal level MS of the molten metal M supplied from the holding chamber 10 to the pressurizing chamber 20 via the on-off valve 17 has reached a desired level. When the controller 70 acquires the information that the molten metal level detection rod 23 has detected the molten metal surface MS, the controller 70 instructs the cylinder 17D to close the on-off valve 17.

The holding chamber 10 and the pressurizing chamber 20 are provided with a heater (not shown) for heating the stored molten metal M at a temperature required for maintaining the molten state of the molten metal M, for example, about 500 ° C. to 700 ° C. Can be installed.

[Casting die 40]
The casting mold 40 includes a fixed mold 41 and a movable mold 43 provided above the fixed mold 41. When the fixed mold 41 and the movable mold 43 are closed as shown in FIG. 1, a casting cavity 42 which is a gap between the fixed mold 41 and the movable mold 43 is formed. The molten metal M supplied from the pouring chamber 30 is discharged into the casting cavity 42. At the center of the fixed mold 41 and the movable mold 43, a pin passage 44, which is a gap for raising and lowering the center pin 49, which will be described later, is formed.
The cast mold 40 also includes other elements such as a fixed plate that supports the fixed mold 41, a movable plate and a fixed plate that support the movable mold 43, and an accessory of the movable plate, but the illustration is omitted. Further, although not shown, a passage for flowing cooling water can be formed in the fixed mold 41, the movable mold 43, the center pin 49 described later, and the like.
In the casting mold 40, it is preferable that the mating surface of the fixed mold 41 and the movable mold 43 is provided with a seal in order to avoid suction of air. Further, although the casting mold 40 is provided with an extrusion pin (not shown) for extruding the cast product, it is preferable to similarly provide a seal for the gap between the extrusion pin and the mold.

The casting mold 40 includes a hot water supply pipe 45 provided above the hot water pouring chamber 30 and a sprue 47 provided above the hot water supply pipe 45. The hot water supply pipe 45 and the sprue 47 serve as a passage for supplying the molten metal M stored in the pouring chamber 30 to the casting cavity 42 formed of the fixed mold 41 and the movable mold 43.

The casting die 40 includes a center pin 49 arranged so that the axial direction C is along the vertical direction V. The center pin 49 includes a small diameter portion 49A and a large diameter portion 49B located above the small diameter portion 49A.
The center pin 49 can be moved up and down between a closed position that closes the sprue 47 and the pin passage 44 and an open position that opens the sprue 47 and the pin passage 44. The movement of the center pin 49 from the closed position to the open position is referred to as retreat, and vice versa. The center pin 49 in FIG. 1 is in the closed position, and the center pin 49 in FIG. 3A is in the open position. If the center pin 49 is in the closed position, the molten metal M cannot be poured into the casting cavity 42, but if the center pin 49 recedes from the closed position to the open position, the molten metal M can be filled in the casting cavity 42. become.
Although the illustration of the drive source for moving the center pin 49 is omitted, a hydraulic cylinder and other power generation sources are applied.

The casting die 40 includes a tubular guide 48 that guides the elevating motion of the center pin 49. The lower end of the tubular guide 48 is fixed to the inner peripheral edge of the movable mold 43 and surrounds the pin passage 44. In the center pin 49, at the closed position shown in FIG. 1, the small diameter portion 49A closes the sprue 47, and the large diameter portion 49B is supported by the tubular guide 48. When the center pin 49 is in the open position shown in FIG. 3A, the large diameter portion 49B is supported by the tubular guide 48, but the molten metal M is surrounded by the tubular guide 48 around the small diameter portion 49A. A hot water pool 46, which is a gap through which the water passes, is formed. As described above, in the center pin 49, the small diameter portion 49A mainly plays a function of closing. Further, if the large diameter portion 49B advances to the molten metal pool 46 after the molten metal M is filled in the casting cavity 24, it functions as a presser for applying metal pressure to the molten metal M.

The tubular guide 48 includes an inner peripheral surface 48C on which the large diameter portion 49B of the center pin 49 slides. Between the outer peripheral surface and the inner peripheral surface 48C of the large diameter portion 49B, a minute gap is provided so that the gas can pass through but the molten metal M cannot pass through. Therefore, the tubular guide 48 is hermetically sealed to the molten metal by the center pin 49 in the range where it is in sliding contact with the center pin 49. A sealing lid 48A is provided at the upper end of the tubular guide 48, and a liquid-tight pressure reducing chamber 48B is formed between the center pin 49 and the sealing lid 48A.
Further, the gap between the outer peripheral surface of the small diameter portion 49A of the center pin 49 and the inner peripheral surface of the sprue 47 is similar to the gap between the outer peripheral surface of the large diameter portion 49B and the inner peripheral surface 48C, and the liquid is liquid with respect to the molten metal. It is tightly sealed.

[Decompression mechanism 50]
The decompression mechanism 50 includes a first vacuum tank 51A, a cavity suction pipe 52 connecting the first vacuum tank 51A and the casting die 40, a second vacuum tank 51B independent of the first vacuum tank 51A, and a second vacuum tank 51B. A vacuum chamber suction pipe 53 for connecting the vacuum chamber 48B and the vacuum chamber 48B is provided. The cavity suction pipe 52 is provided with an on-off valve 55 that selects on / off the action of vacuum suction on the casting die 40 by the vacuum tank 51. Although not shown, the pressure reducing chamber suction pipe 53 is also provided with a similar on-off valve.
The inside of the vacuum tank 51A and the vacuum tank 51B is maintained at a predetermined degree of vacuum by connecting a vacuum pump (not shown).

The cavity suction pipe 52 communicates with the casting cavity 42, and the inside of the casting cavity 42 is mainly depressurized by vacuum suction. The cavity suction pipe 52 is provided with a chill vent 54. The chill vent 54 prevents the molten metal M from entering the cavity suction pipe 52.
The decompression chamber suction pipe 53 penetrates the sealing lid 48A and communicates with the decompression chamber 48B, and the sprue 47 is depressurized mainly from behind the center pin 49 by vacuum suction. The on-off valve 55 is provided in the collecting pipe 53C, and when the on-off valve 55 is closed, vacuum suction is not performed through both the cavity suction pipe 52 and the pressure reducing chamber suction pipe 53. FIG. 1 shows a closed on-off valve 55. When the on-off valve 55 is opened, vacuum suction is performed through both the cavity suction pipe 52 and the pressure reducing chamber suction pipe 53. 2 (b) and 3 (a) show an open on-off valve 55.

[Casting procedure]
Next, the procedure of casting by the casting apparatus 1 will be described with reference to FIGS. 2, 3 and 4.

[Blockage of sprue]
The casting procedure by the casting apparatus 1 is started in a state where the center pin 49 closes the sprue 47 at the closed position as shown in FIGS. 2 (a) and 4 (S101). Further, gas passes between the outer peripheral surface of the large diameter portion 49B of the center pin 49 and the inner peripheral surface 48C, and between the outer peripheral surface of the small diameter portion 49A of the center pin 49 and the inner peripheral surface of the sprue 47. However, a minute gap is provided so that the molten metal M cannot pass through.

[Decompression by vacuum suction part 1]
Next, the on-off valve of the pressure reducing chamber suction pipe 53 (not shown) is opened. Then, the space between the sprue 47 and the sprue surface MS, that is, the molten metal M passes through between the large diameter portion 49B of the center pin 49 and the tubular guide 48 and between the small diameter portion 49A of the center pin 49 and the sprue 47. Since the path to be vacuum is sucked, the path is depressurized (FIG. 4, S103). At this time, the on-off valve 55 is closed, and no vacuum suction force acts on the cavity suction pipe 52. Further, the center pin 49 is in the closed position.
Here, since the gap between the center pin 49 and the tubular guide 48 is minute and the time for obtaining a desired degree of vacuum becomes long, the vacuum suction from the pressure reducing chamber suction pipe 53 is preceded by the cavity suction pipe 52. Is preferable.

[Decompression by vacuum suction part 2]
Next, the on-off valve 55 is opened as shown in FIG. 2B with the center pin 49 still closing the sprue 47. Then, the casting cavity 42 is vacuum-sucked through the cavity suction pipe 52, so that the casting cavity 42 is depressurized (FIG. 4 (S105)).
Here, it has been explained that the cavity suction pipe 52 is responsible for reducing the pressure in the casting cavity 42, and the pressure reducing chamber suction pipe 53 is responsible for reducing the pressure around the sprue 47. However, the cavity suction pipe 52 is also involved in the vacuum suction around the sprue 47, and the decompression chamber suction pipe 53 is also involved in the vacuum suction of the casting cavity 42.
As described above, in the casting apparatus 1 of the present embodiment, the region through which the molten metal M passes, including the casting cavity 42, is depressurized before the molten metal M is filled. This depressurization is continued while applying the pressing force to the molten metal surface MS by the next inert gas.

[Applying pressure by gas]
With the center pin 49 still closing the sprue 47, as shown in FIGS. 2 (c) and 4 (S107), an inert gas is supplied to the pressurizing chamber 20 via the gas supply path 21 and added. A pressing force by gas is applied to the surface MS of the molten metal M in the pressure chamber 20. This pressing force is preferably performed until the molten metal M in the pouring chamber 30 comes into contact with the center pin 49 arranged at the sprue 47, as shown in FIG. 2C. At this time, more preferably, the molten metal surface MS of the molten metal M presses the center pin 49 upward in the vertical direction V. However, this is only a preferable condition in the present invention. Even if the molten metal M is separated from the center pin 49, it does not hinder the rapid filling of the molten metal due to the depressurization and the pressing force in the present invention. The pressure applied by the gas to the molten metal surface MS in the pressurizing chamber 20 is continued.

[Opening the sprue]
After the molten metal M rises until it comes into contact with the center pin 49, when the center pin 49 is retracted to the open position as shown in FIGS. 3 (a) and 4 (S109), the molten metal M passes through the sprue 47 and the casting cavity. 42 is filled. Since the region through which the molten metal M passes, including the casting cavity 42, is depressurized, the resistance when the molten metal M is filled into the casting cavity 42 becomes smaller than the pressure applied by the inert gas in the pressurizing chamber 20 alone. ..
It is also preferable to apply a depressurizing force by vacuum suction and a pressing force by an inert gas for a predetermined period after the molten metal M is filled in the casting cavity 42.

[Blocking the sprue / releasing gas pressurization]
After the molten metal M is filled in the casting cavity 42, the center pin 49 is advanced to the closed position as shown in FIGS. 3 (b) and 4 (S111). Next, the supply of the inert gas to the pressurizing chamber 20 is stopped, and the pressing force of the molten gas M by the inert gas is released. Then, the molten metal surface MS of the molten metal M other than that filled in the casting cavity 42 is lowered.
When the center pin 49 advances to the closed position, the molten metal M filled in the casting cavity 42 is pressurized. This pressurization contributes to filling the end portion of the casting cavity 42, particularly the narrow portion of the runner, with the molten metal M.
In the above, it has been described that the advance to the closed position of the center pin 49 is performed in advance, but the opposite, that is, after the pressing and depressurizing are released in advance, to the closed position of the center pin 49. May be advanced, or pressurization and depressurization may be released and advancement to the closed position of the center pin 49 may be performed in parallel.

[Metal pressure addition]
Next, as shown in FIG. 3C, the center pin 49 is advanced from the conventional closed position until the large diameter portion 49B of the center pin 49 reaches the hot water pool 46. Then, the volume of the basin 46 is reduced by the difference between the small diameter portion 49A and the large diameter portion 49B of the center pin 49, and the molten metal M having the volume of the molten metal corresponding to this reduction in volume is cast from the basin 46. It is supplied to the cavity 42. Further, in this supply process, a pressing force obtained by dividing the forward driving force applied to the center pin 49 by the pressurized area due to the difference in outer diameter between the large diameter portion 49B and the small diameter portion 49A, that is, a metal pressure is applied. Then, since the molten metal is supplied from the hot water pool 46, the so-called hot water pressing effect is exhibited (FIG. 4, S113). In this hot water pressing effect, it is preferable that the molten metal M for the solidification shrinkage is supplied to the casting cavity 42 in an appropriate amount according to the progress of the solidification shrinkage.

[Decompression release]
When the molten metal M for the solidification shrinkage is replenished, the decompression via the cavity suction pipe 52 connected to the first vacuum tank 51A and the pressure reducing chamber suction pipe 53 connected to the second vacuum tank 51B is released (S115).

Hereinafter, although not shown, the casting product is made after the molten metal M has solidified in the casting cavity 42, the fixed mold 41 and the movable mold 43 are opened, and the center pin 49 is retracted to the open position. Is taken out and a series of casting processes is completed.
After closing the fixed mold 41 and the movable mold 43, as shown in FIG. 2A, if the center pin 49 is advanced to the closed position, the next casting process can be started.

[Effect of casting device 1]
According to the casting method by the casting apparatus 1, the region through which the molten metal M passes, including the casting cavity 42, is depressurized before the molten metal M is filled, so that the resistance when the molten metal M is filled in the casting cavity 42 is small. .. Therefore, since the molten metal M is quickly filled in the casting cavity 42, the temperature drop of the molten metal M filled in the casting cavity 42 is small. As a result, the propagation range of the pressing force applied from the center pin 49 to the molten metal M filled in the casting cavity 42 by the center pin 49 becomes wide. Therefore, the molten metal M can be sufficiently filled in the minute width portion at the end of the casting cavity 42, so that a high quality cast product can be obtained.

In addition, according to the casting apparatus 1 of the present embodiment, air is discharged from the decompression chamber 48B on the back surface of the center pin 49 via the decompression chamber suction pipe 53, so that a high-quality casting product in which air entrainment is suppressed is suppressed. Can be obtained. In particular, since the casting apparatus 1 continues the reduced pressure suction until the metal pressure is applied by the center pin 49, a higher quality cast product can be obtained.

Although the present invention has been described above based on the preferred embodiment, the configuration described in the present embodiment can be selected or changed as appropriate without departing from the gist of the present invention.
For example, in the present embodiment, the casting apparatus 1 provided with the holding chamber 10, the pressurizing chamber 20, and the pouring chamber 30 is taken as an example, but in the present invention, the lower end is provided in the pouring chamber received below the casting mold. It can also be applied to casting equipment in which the molten metal is filled into the casting cavity through the immersed stalk. In this casting apparatus, a pressing force by gas is applied to the surface of the hot water outside the hot water supply pipe in the pouring chamber. That is, in the present invention, applying a pressing force by gas in order to raise the surface of the molten metal stored in the pouring chamber means that the pressing force is directly applied to the molten metal stored in the pouring chamber. , Includes a form in which a pressing force is indirectly applied to the molten metal stored in the pouring chamber. The above-described embodiment corresponds to the latter embodiment.

Further, in the present embodiment, a preferable example in which two vacuum suction paths of the cavity suction pipe 52 and the pressure reducing chamber suction pipe 53 are provided has been shown, but the present invention is not limited thereto. If the circumferences of the casting cavity 42 and the sprue 47 can be depressurized, only one of the cavity suction pipe 52 and the decompression chamber suction pipe 53 can be provided.

Further, the casting apparatus 1 in the present embodiment shows an example in which the center pin 49 is arranged at the center of the fixed mold 41 and the movable mold 43 in the horizontal direction, but the present invention is not limited thereto. Regardless of the position, the present invention can be applied as long as it has a closed body that can move up and down between the closed position that closes the sprue and the open position that opens the sprue.

1 Casting equipment 10 Holding chamber 13 Molten passage 14 Lid 15 Bottom wall 16 Supply port 17 On-off valve 20 Pressurizing chamber 21 Gas supply path 23 Hot water level detection rod 30 Pouring chamber 40 Casting die 41 Fixed mold 42 Casting cavity 43 Movable Mold 44 Pin passage 45 Hot water supply pipe 46 Hot water reservoir 47 Hot water outlet 48 Cylindrical guide 48A Sealing lid 48B Decompression chamber 48C Inner peripheral surface 49 Center pin (closed body)
49A Small diameter part 49B Large diameter part 50 Decompression mechanism 51A 1st vacuum tank 51B 2nd vacuum tank 52 Cavity suction pipe 53 Decompression chamber suction pipe 54 Chill vent 55 On-off valve 70 Controller C Axial direction M Molten metal MS Hot water surface

Claims (8)

A casting die with a casting cavity filled with molten metal through a sprue,
A closing body that moves between a closing position that closes the sprue and an opening position that opens the sprue,
The pouring room where the molten metal is stored and
A gas pressure applying mechanism that applies a pressing force by gas to raise the surface of the molten metal stored in the pouring chamber,
A decompression mechanism for depressurizing the casting cavity and the sprue is provided.
In a state where the sprue is closed by the closed body at the closed position, the casting cavity and the sprue are depressurized by the depressurizing mechanism, and the molten metal is subjected to the pressing force by gas by the gas pressure applying mechanism.
Next, the closed body is moved to the open position, and the closed body is maintained in the open position.
Next, the closed body is advanced to the closed position, and the pressing force is released by the gas pressure applying mechanism and the decompression is released by the depressurizing mechanism in order.
A casting machine characterized by that.
After the closed body advances to the closed position, a metal pressure is applied to the molten metal in the casting cavity to replenish the solidification shrinkage of the molten metal, and then the depressurization is released.
The casting apparatus according to claim 1.
The decompression mechanism includes a decompression chamber behind the obstructor.
The decompression force is applied through the decompression chamber.
The casting apparatus according to claim 1 or 2.
The decompression mechanism
A first vacuum tank, a cavity suction pipe connected to the first vacuum tank and communicating with the casting cavity,
A second vacuum tank independent of the first vacuum tank and a pressure reducing chamber suction pipe connected to the second vacuum tank and communicating with the decompression chamber are provided.
The casting apparatus according to claim 2.
After performing the decompression from the decompression chamber suction tube through the decompression chamber in advance,
Depressurize the cast cavity from the cavity suction tube.
The casting apparatus according to claim 4.
With the sprue closed by the closed body, the decompression and the pressing force are applied, and after the molten metal comes into contact with the closed body, the closed body is moved to the open position.
The casting apparatus according to any one of claims 1 to 5.
A casting method in which the molten metal stored in the pouring chamber is filled into the casting cavity through the sprue.
In the state where the sprue is closed, the first step of depressurizing the casting cavity, the sprue, and the space below the sprue, and applying a pressing force by gas to the surface of the molten metal.
The second step of releasing the blockage of the sprue and filling the casting cavity with the molten metal while applying the depressurizing pressure and the pressing force.
The third step, in which the sprue is closed and the pressing force and the depressurizing force are released in order,
A casting method characterized by comprising.
In the third step,
After replenishing the solidification shrinkage of the molten metal in the casting cavity, the depressurization is released.
The casting method according to claim 7.

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