JP2017001084A - Pull-up type continuous casting apparatus and pull-up type continuous casting method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pull-up type continuous casting apparatus and a pull-up type continuous casting method which can prevent a molten metal led out of a molten metal surface from flowing into the inside of a hollow casting.SOLUTION: A pull-up type continuous casting apparatus related to one aspect of this invention, which is a pull-up type continuous casting apparatus comprising a molten metal holding furnace 101 that holds a molten metal M1, a shape regulation member 102 installed on the molten metal surface of the molten metal M1 to regulate the cross-sectional shape of a hollow casting M3 cast by the passage of a holding molten metal M2 led out of the molten metal surface, and a cooling part 109 that cools the holding molten metal M2 continuous via the casting M3 and a solidification interface by spraying a cooling gas onto the inner peripheral surface of the hollow casting M3 in a vicinity of the solidification interface, further comprises a blowing part 116 that blows air to a negative-pressure region generated in a space between a channel of a cooling gas sprayed out of the cooling part 109 and the top face of the shape regulation member 102.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an up-drawing continuous casting apparatus and an up-drawing continuous casting method.

  Patent Document 1 discloses a pull-up type continuous casting method that does not require a mold. As shown in Patent Document 1, when a starter is immersed in the surface of molten metal (molten metal) (that is, the molten metal surface) and then the starter is pulled up, the molten metal is derived by following the starter by the surface film and surface tension of the molten metal. Is done. Here, a casting having a desired cross-sectional shape can be continuously cast by deriving and cooling the molten metal through a shape determining member installed in the vicinity of the molten metal surface.

JP-A-9-248657

The inventor has found the following problems.
In the continuous casting method described in Patent Document 1, a hollow casting (hollow casting) may be cast. In this case, solidification of the melt derived from the molten metal surface is promoted by blowing cooling gas to the outer peripheral surface and inner peripheral surface of the hollow casting near the solidification interface and indirectly cooling the molten metal derived from the molten metal surface. Can be made. However, when cooling gas is blown onto the inner peripheral surface of the hollow casting near the solidification interface, a negative pressure region is formed in the space between the flow path of the blown cooling gas and the upper surface of the shape defining member due to the influence of the air flow. There was a problem that the molten metal led out from the molten metal surface was pulled by the negative pressure and flowed into the hollow casting.

  The present invention has been made in view of the above, and includes a pulling-up-type continuous casting apparatus and a pulling-up-type continuous casting method capable of suppressing the molten metal led out from the molten metal surface from flowing into the inside of the hollow casting. The purpose is to provide.

  The up-drawing continuous casting apparatus according to an aspect of the present invention is cast by a holding furnace for holding a molten metal and the molten metal that is installed on the molten metal surface and that is led out from the molten metal surface. A shape-defining member that defines the cross-sectional shape of the hollow casting, and is derived from the molten metal surface that is continuous with the hollow casting and the solidification interface by blowing cooling gas to the inner peripheral surface of the hollow casting near the solidification interface. And a cooling unit that cools the molten metal, and is provided between a flow path through which the cooling gas blown out from the cooling unit flows and an upper surface of the shape defining member. A blower for blowing air to a negative pressure region generated in the space is further provided. Thereby, since the negative pressure state of the negative pressure region is relaxed, it is possible to suppress the molten metal led out from the molten metal surface from flowing into the hollow casting.

  It is preferable that the blower port of the blower part is provided above the cooling part inside the hollow casting and blows air toward the negative pressure region below. Thereby, since it is not necessary to install the nozzle in the holding furnace, it is easy to install the blower.

  It is preferable that the air outlet of the air blower is disposed on a member that contacts the negative pressure region and opens toward the negative pressure region. As a result, it becomes possible to send the wind more accurately into the negative pressure region, so that the negative pressure state in the negative pressure region is more reliably relaxed.

  It is preferable that a pressure sensor for measuring the pressure in the negative pressure region is further provided, and the blowing unit blows air at a flow rate corresponding to a measurement result of the pressure sensor. As a result, it becomes possible to send in a wind having a flow rate suitable for alleviating the negative pressure state in the negative pressure region, so that the negative pressure state in the negative pressure region is more accurately relaxed.

  In the up-drawing continuous casting method according to one aspect of the present invention, the molten metal is led out from the surface of the molten metal held in a holding furnace, and passed through a shape defining member that defines the cross-sectional shape of the hollow casting, An up-drawing continuous casting method for casting the hollow casting, wherein the hot water is continuous with the hollow casting through the solidification interface by blowing a cooling gas to an inner peripheral surface of the hollow casting near the solidification interface. Cooling the molten metal derived from a surface, blowing air to a negative pressure region generated in a space between the flow path of the blown-out cooling gas and the upper surface of the shape defining member; Is provided. Thereby, since the negative pressure state of the negative pressure region is relaxed, it is possible to suppress the molten metal led out from the molten metal surface from flowing into the hollow casting.

  According to the present invention, it is possible to provide a pulling-up-type continuous casting apparatus and a pull-up-type continuous casting method that can suppress the molten metal led out from the molten metal surface from flowing into the inside of the hollow casting.

1 is a cross-sectional view schematically showing a free casting apparatus according to Embodiment 1. FIG. It is a top view of the shape prescription | regulation member shown in FIG. It is a figure for demonstrating the subject of the free casting apparatus which concerns on a comparative example. It is a figure for demonstrating the subject of the free casting apparatus which concerns on a comparative example. It is an expanded sectional view which shows a part of free casting apparatus shown in FIG. 3 is a flowchart showing a free casting method according to Embodiment 1. It is a figure which shows the relationship between the flow volume of a cooling gas, and the pressure difference of the pressure of a negative pressure area | region, and atmospheric pressure. It is sectional drawing which shows typically the free casting apparatus which concerns on Embodiment 2. FIG. 6 is an enlarged cross-sectional view showing a part of a free casting apparatus according to Embodiment 3. FIG. It is a top view which shows the shape prescription | regulation member periphery shown in FIG. It is an expanded sectional view which shows a part of modification of the free casting apparatus shown in FIG. It is a top view which shows the shape prescription | regulation member periphery shown in FIG.

  Hereinafter, specific embodiments to which the present invention is applied will be described in detail with reference to the drawings. However, the present invention is not limited to the following embodiment. In addition, for clarity of explanation, the following description and drawings are simplified as appropriate.

<Embodiment 1>
First, with reference to FIG. 1, the free casting apparatus (pull-up type continuous casting apparatus) according to Embodiment 1 will be described. 1 is a cross-sectional view schematically showing a free casting apparatus according to Embodiment 1. FIG. As shown in FIG. 1, a free casting apparatus according to Embodiment 1 includes a molten metal holding furnace (holding furnace) 101, a shape defining member 102, support rods 106 and 107, an actuator 108, a cooling unit 109, a blower unit 116, and A puller 115 is provided. In FIG. 1, right-handed xyz coordinates are shown for the sake of convenience in order to explain the positional relationship between the components. The xy plane in FIG. 1 constitutes a horizontal plane, and the z-axis direction is the vertical direction. More specifically, the positive direction of the z axis is vertically upward.

  The molten metal holding furnace 101 accommodates a molten metal M1 such as aluminum or an alloy thereof, and holds the molten metal M1 at a predetermined temperature having fluidity. In the example of FIG. 1, since the molten metal is not replenished to the molten metal holding furnace 101 during casting, the surface of the molten metal M1 (that is, the molten metal surface) decreases as the casting progresses. On the other hand, the molten metal may be replenished to the molten metal holding furnace 101 at any time during casting to keep the molten metal surface constant. Here, when the set temperature of the molten metal holding furnace 101 is raised, the position of the solidification interface SIF can be raised, and when the set temperature of the molten metal holding furnace 101 is lowered, the position of the solidified interface SIF can be lowered. As a matter of course, the molten metal M1 may be a metal other than aluminum or an alloy thereof.

  The shape defining member 102 is made of, for example, ceramics or stainless steel, and is disposed on the molten metal surface. The shape defining member 102 includes an external shape defining member 103 and an internal shape defining member 104. The external shape defining member 103 defines the external cross-sectional shape of the casting M3 to be cast, and the internal shape defining member 104 defines the internal cross-sectional shape of the cast M3 to be cast. The casting M3 shown in FIG. 1 is a hollow casting (that is, a pipe) having a horizontal cross section (hereinafter referred to as a transverse section) having a tubular shape.

  In the example of FIG. 1, the external shape defining member 103 and the internal shape defining member 104 are arranged such that their lower main surfaces (lower surfaces) are in contact with the hot water surface. Thereby, mixing of the oxide film formed on the surface of the molten metal M1 and the foreign matter floating on the surface of the molten metal M1 into the casting M3 is suppressed. On the other hand, the outer shape defining member 103 and the inner shape defining member 104 may be installed such that their lower surfaces do not contact the molten metal surface. Specifically, the outer shape defining member 103 and the inner shape defining member 104 may be arranged such that their lower surfaces are separated from the molten metal surface by a predetermined distance (for example, about 0.5 mm). Thereby, in the external shape defining member 103 and the internal shape defining member 104, since thermal deformation and melting damage are suppressed, durability is improved.

  FIG. 2 is a plan view of the shape defining member 102 shown in FIG. Here, the cross-sectional view of the shape determining member 102 in FIG. 1 corresponds to the II cross-sectional view in FIG. 2. In the example of FIG. 2, the external shape defining member 103 has, for example, a rectangular planar shape, and has a circular opening at the center. The internal shape defining member 104 has a circular planar shape and is disposed at the center of the opening of the external shape defining member 103. A gap between the outer shape defining member 103 and the inner shape defining member 104 becomes a molten metal passage portion 105 through which the molten metal passes. Note that the xyz coordinates in FIG. 2 coincide with those in FIG.

  Here, FIG. 2 also shows the nozzle tip 114 of the cooling unit 109. The nozzle tip 114 is disposed at the center of the internal shape defining member 104. The nozzle tip portion 114 is provided with a plurality of cooling gas outlets 114 a that open toward the melt passage portion 105 in plan view.

  The pulling machine 115 holds the starter (leading member) ST and immerses the starter ST in the molten metal M1 or pulls up the starter ST immersed in the molten metal M1.

  As shown in FIG. 1, after the molten metal M1 is coupled to the immersed starter ST, the molten metal M1 is pulled up following the starter ST while maintaining its outer shape by its surface film and surface tension, and the molten metal passage portion of the shape defining member 102 Go through 105. When the molten metal M1 passes through the molten metal passage portion 105 of the shape defining member 102, an external force is applied to the molten metal M1 from the shape defining member 102, and the cross-sectional shape of the casting M3 is defined. Here, the molten metal pulled up from the molten metal surface following the starter ST (or the casting M3 formed by solidification of the molten metal M1 pulled up following the starter ST) by the surface film or surface tension of the molten metal M1. This is called retained molten metal M2. Further, the boundary between the casting M3 and the retained molten metal M2 is a solidification interface SIF.

  The support rod 106 supports the external shape defining member 103, and the support rod 107 supports the internal shape defining member 104. Both of the support rods 106 and 107 are connected to the actuator 108.

  The actuator 108 can move the external shape defining member 103 and the internal shape defining member 104 in the vertical direction (z-axis direction) via the support rods 106 and 107. Thereby, the shape determining member 102 can be moved downward as the molten metal surface is lowered due to the progress of casting.

  The cooling unit 109 is a unit that indirectly cools the retained molten metal M2 by blowing a cooling gas (for example, air, nitrogen, argon, or the like) onto the starter ST or the casting M3. Increasing the flow rate of the cooling gas can lower the position of the solidification interface SIF, and decreasing the flow rate of the cooling gas can increase the position of the solidification interface SIF. The cooling unit 109 is also movable in the vertical direction (vertical direction; z-axis direction) and in the horizontal direction (x-axis direction and y-axis direction). Therefore, for example, along with the lowering of the molten metal surface due to the progress of casting, the cooling unit 109 can be moved downward in accordance with the downward movement of the shape defining member 102. Alternatively, the cooling unit 109 can be moved in the horizontal direction in accordance with the horizontal movement of the puller 115 and the shape defining member 102.

  More specifically, the cooling unit 109 includes a cooling gas supply unit 110, nozzles 111 and 112, and nozzle tip portions 113 and 114. The cooling unit 109 blows out the cooling gas supplied from the cooling gas supply unit 110 from the nozzle tip portions 113 and 114 via the nozzles 111 and 112, respectively.

  The nozzle tip 113 is provided outside the casting M3 so as to surround the outer peripheral surface of the casting M3. The plurality of cooling gas blowing ports provided at the nozzle tip 113 are open toward the outer peripheral surface of the casting M3 in the vicinity of the solidification interface SIF. The nozzle tip 113 sprays the cooling gas blown from the plurality of cooling gas blowout ports onto the outer peripheral surface of the casting M3 in the vicinity of the solidification interface SIF.

  The nozzle tip 114 is provided inside the casting M3 (in this example, the center of the internal shape defining member 104). The plurality of cooling gas outlets 114a provided at the nozzle tip 114 are open toward the inner peripheral surface of the casting M3 near the solidification interface SIF. The nozzle tip 114 blows the cooling gas blown from the plurality of cooling gas blowout ports 114a onto the inner peripheral surface of the casting M3 in the vicinity of the solidification interface SIF.

  The molten metal M2 in the vicinity of the solidification interface SIF is lowered from the upper side (the z-axis direction plus side) by pulling up the casting M3 by the puller 115 connected to the starter ST and cooling the starter ST and the casting M3 with the cooling gas. The casting M3 is sequentially solidified to the side (z-axis direction minus side) to form a casting M3. Increasing the pulling speed by the puller 115 can raise the position of the solidification interface SIF, and decreasing the pulling speed can lower the position of the solidification interface SIF.

  Moreover, the holding molten metal M2 can be derived | led-out in the diagonal direction by pulling up, moving the pulling machine 115 to a horizontal direction (x-axis direction or y-axis direction). Therefore, the shape of the casting M3 in the longitudinal direction can be freely changed. Note that the shape of the casting M3 in the longitudinal direction may be freely changed by moving the shape defining member 102 in the horizontal direction instead of moving the pulling machine 115 in the horizontal direction.

  The blowing part 116 is a part that blows air against the negative pressure region X generated by blowing cooling gas to the inner peripheral surface of the casting M3 in the vicinity of the solidification interface SIF. Details of the negative pressure region X will be described later.

  More specifically, the air blowing unit 116 includes a wind supply unit 117, a nozzle 118, and a nozzle tip 119. The air blowing unit 116 blows the wind (air, the same type of gas as the cooling gas) supplied from the wind supply unit 117 from the nozzle tip 119 via the nozzle 118.

  The nozzle tip 119 is arranged so as to be hung from the vicinity of the pulling machine 115 by the nozzle 118 inside the hollow casting M3 (inside the cylinder). The plurality of air outlets 119 a provided in the nozzle tip 119 are located above the nozzle tip 114 of the cooling unit 109 and open toward the negative pressure region X below. Blow. In the case of the arrangement of the air blowing unit 116 as described above, it is not necessary to install the nozzle 118 in the molten metal holding furnace 101, so that the air blowing unit 116 is easily installed.

  Hereinafter, the problem caused by the generation of the negative pressure region X and the effect of using the air blowing unit 116 will be described with reference to FIGS.

  3 and 4 are diagrams for explaining the problem of the free casting apparatus according to the comparative example. The free casting apparatus shown in FIGS. 3 and 4 is not provided with the blower unit 116. FIG. 5 is an enlarged sectional view showing a part of the free casting apparatus shown in FIG.

  As shown in FIG. 3, a flow path (black arrow in the figure) through which the cooling gas blown out from the plurality of cooling gas blowing ports 114 a provided at the nozzle tip 114, the upper surface of the internal shape defining member 104, The space between is in a negative pressure state showing a pressure value lower than the atmospheric pressure due to the influence of the cooling gas flow. This negative pressure space is called a negative pressure region X.

  As shown in FIG. 4, when the ventilation part 116 is not provided, the holding | maintenance molten metal M2 which contact | connects the negative pressure area | region X may be pulled by the negative pressure, and may flow in the inside of the hollow shaped casting M3. In order to avoid this, the flow rate of the cooling gas must be reduced to suppress the generation of the negative pressure region X. However, if the flow rate of the cooling gas is reduced, it takes time for the retained molten metal M2 to solidify, and the productivity of the casting M3 decreases.

  On the other hand, as shown in FIG. 5, when the blower unit 116 is provided, the negative pressure state of the negative pressure region X is relieved by blowing air from the blower unit 116 to the negative pressure region X. That is, the differential pressure between the pressure in the negative pressure region X and the atmospheric pressure is reduced. Therefore, it is possible to suppress the retained molten metal M2 from flowing into the hollow casting M3 without reducing the flow rate of the cooling gas.

  Next, the free casting method according to the first embodiment will be described with reference to FIGS. 1 and 6. FIG. 6 is a flowchart illustrating the free casting method according to the first embodiment.

  First, the starter ST is lowered by the pulling machine 115, and the front end portion (lower end portion) of the starter ST is immersed in the molten metal M1 through the molten metal passage portion 105 between the external shape defining member 103 and the internal shape defining member 104 ( Step S101).

  Next, the starter ST is started to be pulled up at a predetermined speed. Here, even if the starter ST is separated from the molten metal surface, the molten metal M1 is pulled up (derived) from the molten metal surface by the surface film or surface tension to form the retained molten metal M2. As shown in FIG. 1, the retained molten metal M <b> 2 is formed in the molten metal passage portion 105 of the shape defining member 102. That is, the shape defining member 102 imparts a shape to the retained molten metal M2 (step S102).

  Next, the starter ST and the casting M3 are cooled by the cooling gas blown out from the cooling unit 109 (step S103). Thereby, the retained molten metal M2 is indirectly cooled and solidified in order from the upper side to the lower side, and the casting M3 grows (step S104). In this way, the casting M3 can be continuously cast.

  Here, in the space between the flow path of the cooling gas blown out from the plurality of cooling gas outlets 114 a provided at the nozzle tip 114 and the upper surface of the internal shape defining member 104, there is an air flow of the cooling gas. The negative pressure region X is generated due to the influence of. Then, it blows with respect to the negative pressure area | region X from the ventilation part 116 (step S103). Thereby, the negative pressure state of the negative pressure region X is relaxed. That is, the differential pressure between the pressure in the negative pressure region X and the atmospheric pressure is reduced. Thereby, it is possible to suppress the retained molten metal M2 from flowing into the inside of the hollow casting M3.

  FIG. 7 is a diagram illustrating the relationship between the flow rate of the cooling gas and the differential pressure between the pressure in the negative pressure region X and the atmospheric pressure. Referring to FIG. 7, when the flow rate of the cooling gas is zero, the negative pressure region X does not occur (the differential pressure is zero), but the negative pressure in the negative pressure region X increases as the flow rate of the cooling gas increases. (The pressure difference between the pressure in the negative pressure region X and the atmospheric pressure increases). In addition, when the flow rate of the cooling gas is constant, the smaller the area of the cooling gas outlet 114a, the higher the flow rate of the cooling gas, and thus the negative pressure in the negative pressure region X increases. Here, the air blower 116 may adjust the air volume by estimating the pressure in the negative pressure region X based on, for example, information shown in FIG.

  Thus, the free casting apparatus according to the present embodiment includes the blower 116 that blows air to the negative pressure region X generated by the influence of the cooling gas blown to the inner peripheral surface of the hollow casting M3. Thereby, since the free casting apparatus concerning this Embodiment can relieve the negative pressure state of the negative pressure area | region X, it can suppress that the hold | maintenance molten metal M2 flows into the inside of the hollow-shaped casting M3. .

<Embodiment 2>
FIG. 8 is a cross-sectional view schematically showing a free casting apparatus according to the second embodiment. The free casting apparatus shown in FIG. 8 further has a feedback function in which the air blowing unit 116 blows with an air volume corresponding to the pressure in the negative pressure region X, as compared with the free casting apparatus shown in FIG. Note that the xyz coordinates in FIG. 8 coincide with those in FIG.

  Specifically, the free casting apparatus shown in FIG. 8 further includes a pressure sensor 120 provided in the negative pressure region X. The pressure sensor 120 measures the pressure in the negative pressure region X. And the ventilation part 116 ventilates with respect to the negative pressure area | region X with the air volume according to the measurement result of the pressure sensor 120. FIG. For example, the air blowing unit 116 reduces the air volume when the differential pressure between the pressure in the negative pressure region X and the atmospheric pressure is small, and increases the air volume when the differential pressure between the pressure in the negative pressure region X and the atmospheric pressure is large. .

  As a result, the free casting apparatus according to the present embodiment can send a wind having a flow rate suitable for alleviating the negative pressure state in the negative pressure region X to the negative pressure region X. The negative pressure state of the pressure region X can be relaxed.

<Embodiment 3>
FIG. 9 is an enlarged cross-sectional view showing a part of the free casting apparatus according to the third embodiment. FIG. 10 is a plan view showing the periphery of the shape defining member 102 shown in FIG. The xyz coordinates in FIGS. 9 and 10 are the same as those in FIG.

  The free casting apparatus shown in FIG. 9 differs from the free casting apparatus shown in FIG. 1 in the arrangement position of the nozzle tip (and the air outlet) provided in the air blowing part 116.

  The free casting apparatus shown in FIG. 9 includes a wind supply unit 117, a nozzle 121, and a plurality of nozzle tip portions 122 as the blower unit 116. A part of the nozzle 121 is installed in the molten metal M1. The nozzle 121 installed in the molten metal M <b> 1 extends from the lower surface of the internal shape defining member 104 to the upper surface through the inside thereof, and is connected to the plurality of nozzle tip portions 122. Referring to FIG. 10, the plurality of nozzle tip portions 122 are provided on the upper surface of the internal shape defining member 104 that is one of the members in contact with the negative pressure region X so as to surround the nozzle tip portion 114 of the cooling unit 109. Yes. The plurality of air blowing ports 122 a provided in each of the plurality of nozzle tip portions 122 are open toward the negative pressure region X.

  The other configuration of the free casting apparatus shown in FIG. 9 is the same as that of the free casting apparatus shown in FIG.

  As a result, the free casting apparatus according to the present embodiment can more accurately feed wind into the negative pressure region X, and therefore can more reliably relieve the negative pressure state in the negative pressure region X.

(Modification of the free casting apparatus shown in FIG. 9)
FIG. 11 is an enlarged sectional view showing a part of a modification of the free casting apparatus shown in FIG. FIG. 12 is a plan view showing the periphery of the shape defining member 102 shown in FIG. The xyz coordinates in FIGS. 11 and 12 are the same as those in FIG.

  The free casting apparatus shown in FIG. 11 differs from the free casting apparatus shown in FIG. 9 in the arrangement position of the nozzle tip (and the air outlet) provided in the air blowing part 116.

  The free casting apparatus shown in FIG. 11 includes a wind supply unit 117, a nozzle 123, and a nozzle tip 124 as the blowing unit 116. A part of the nozzle 123 is installed in the molten metal M1. The nozzle 123 installed in the molten metal M <b> 1 extends from the lower surface of the internal shape defining member 104 to the upper surface through the inside thereof, and is connected to the nozzle tip portion 124. Here, the nozzle tip 124 of the blower 116 shares a cylindrical member that forms the nozzle tip 114 of the cooling unit 109. Referring to FIGS. 11 and 12, the plurality of air outlets 124 a are provided on the side surface of a cylindrical member that forms nozzle tip portions 114 and 124 that are one of the members in contact with the negative pressure region X. Opening toward region X.

  The other configuration of the free casting apparatus shown in FIG. 11 is the same as that of the free casting apparatus shown in FIG.

  As a result, the free casting apparatus according to the present embodiment can more accurately feed wind into the negative pressure region X, and therefore can more reliably relieve the negative pressure state in the negative pressure region X.

  As described above, the free casting apparatus according to Embodiments 1 to 3 blows air to the negative pressure region X generated by the influence of the cooling gas blown to the inner peripheral surface of the hollow casting M3. Is provided. As a result, the free casting apparatus according to the first to third embodiments can relieve the negative pressure state of the negative pressure region X, so that the retained molten metal M2 is prevented from flowing into the hollow casting M3. be able to.

  In the said embodiment, although the case where the casting of a cylindrical shape was cast was demonstrated to the example, it is not restricted to this. The present invention can also be applied when casting other hollow shaped castings such as a rectangular tube shape.

  Note that the present invention is not limited to the above-described embodiment, and can be changed as appropriate without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 101 Molten metal holding furnace 102 Shape defining member 103 External shape defining member 104 Internal shape defining member 105 Melt passage part 106 Support rod 107 Support rod 108 Actuator 109 Cooling part 110 Cooling gas supply part 111 Nozzle 112 Nozzle 113 Nozzle tip part 114 Nozzle tip part 114a Cooling gas outlet 115 Lifter 116 Air blower 117 Air supply part 118 Nozzle 119 Nozzle tip 119a Air blower 120 Pressure sensor 121 Nozzle 122 Nozzle tip 122a Air blower 123 Nozzle 124 Nozzle tip 124a Air blower M1 Molten metal M2 Holding Molten metal M3 casting SIF solidification interface ST starter

Claims (5)

A holding furnace for holding molten metal;
A shape determining member that defines a cross-sectional shape of a hollow casting to be cast by passing through the molten metal that is installed on the molten metal surface and is derived from the molten metal surface;
A cooling unit that cools the hollow casting and the molten metal led out from the molten metal surface through the solidification interface by spraying a cooling gas on the inner peripheral surface of the hollow casting near the solidification interface. A pull-up type continuous casting apparatus,
The pulling-up-type continuous casting apparatus further comprising a blower for blowing air to a negative pressure region generated in a space between the flow path of the cooling gas blown out from the cooling part and the upper surface of the shape defining member. .   The pulling-up-type continuous casting apparatus according to claim 1, wherein the blower port of the blower part is provided above the cooling part in the hollow casting and blows air toward the negative pressure region below.   The pulling-up-type continuous casting apparatus according to claim 1, wherein the blower port of the blower unit is disposed in a member that is in contact with the negative pressure region and opens toward the negative pressure region. A pressure sensor for measuring the pressure in the negative pressure region;
The pulling-up-type continuous casting apparatus according to any one of claims 1 to 3, wherein the blower blows air at a flow rate corresponding to a measurement result of the pressure sensor. A pulling-up-type continuous casting method for casting the hollow casting by deriving the molten metal from a molten metal surface held in a holding furnace and passing a shape defining member that defines a cross-sectional shape of the hollow casting. ,
Cooling the molten metal led out from the molten metal surface that is continuous through the solidified interface by blowing a cooling gas to the inner peripheral surface of the hollow cast near the solidified interface; and
And a step of blowing air to a negative pressure region generated in a space between the flow path of the blown-out cooling gas and the upper surface of the shape defining member.

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