US20160296998A1

US20160296998A1 - Pulling-up-type continuous casting apparatus and pulling-up-type continuous casting method

Info

Publication number: US20160296998A1
Application number: US15/036,585
Authority: US
Inventors: Hiroyuki Ikuta; Naoaki Sugiura
Original assignee: Toyota Motor Corp
Current assignee: Toyota Motor Corp
Priority date: 2013-11-15
Filing date: 2014-10-09
Publication date: 2016-10-13
Also published as: CN105705270A; EP3068563A1; WO2015072074A1; JP6123644B2; CN105705270B; JP2015096270A

Abstract

A pulling-up-type continuous casting apparatus according to an aspect of the present invention includes a molten-metal holding furnace that holds molten metal, a shape defining member disposed in a vicinity of a molten-metal surface in the molten-metal holding furnace, the shape defining member being configured to define a cross-sectional shape of a cast-metal article to be cast as the held molten metal passes through the shape defining member, and an actuator that applies a pressure to the molten metal held in the molten-metal holding furnace and thereby makes the held molten metal pass through the shape defining member.

Description

TECHNICAL FIELD

The present invention relates to a pulling-up-type continuous casting apparatus and a pulling-up-type continuous casting method.

BACKGROUND ART

The inventors of the present application have proposed, in Patent Literature 1, a free casting method as a revolutionary continuous casting method that does not requires any mold. As shown in Patent Literature 1, after a starter is submerged under the surface of a melted metal (molten metal) (i.e., molten-metal surface), the starter is pulled up, so that some of the molten metal follows the starter and is drawn up by the starter by the surface film of the molten metal and/or the surface tension. Note that it is possible to continuously cast a cast-metal article having a desired cross-sectional shape by drawing the molten metal and cooling the drawn molten metal through a shape defining member disposed in the vicinity of the molten-metal surface.
In the ordinary continuous casting method, the shape in the longitudinal direction as well as the shape in cross section is defined by the mold. In the continuous casting method, in particular, since the solidified metal (i.e., cast-metal article) needs to pass through the inside of the mold, the cast-metal article has such a shape that it extends in a straight-line shape in the longitudinal direction. In contrast to this, the shape defining member used in the free casting method defines only the cross-sectional shape of the cast-metal article, while it does not define the shape in the longitudinal direction. Further, since the shape defining member can be moved in the direction parallel to the molten-metal surface (i.e., in the horizontal direction), cast-metal articles having various shapes in the longitudinal direction can be produced. For example, Patent Literature 1 discloses a hollow cast-metal article (i.e., a pipe) having a zigzag shape or a helical shape in the longitudinal direction rather than the straight-line shape.

CITATION LIST

Patent Literature

[PTL 1]: Japanese Unexamined Patent Application Publication No. 2012-61518

SUMMARY OF INVENTION

Technical Problem

The present inventors have found the following problem. Namely, in the free casting method disclosed in Patent Literature 1, there is a problem that since the starter has to be replaced every time a new cast-metal article is cast, the productivity of cast-metal articles cannot be improved.
The present invention has been made in view of the above-described problem, and an object thereof is to provide a pulling-up-type continuous casting apparatus and a pulling-up-type continuous casting method capable of improving the productivity of cast-metal articles by applying a pressure to molten metal and thereby making the molten metal pass through a shape defining member without using a starter.

Solution to Problem

A pulling-up-type continuous casting apparatus according to an aspect of the present invention includes: a holding furnace that holds molten metal; a shape defining member disposed in a vicinity of a molten-metal surface of the molten metal, the shape defining member being configured to define a cross-sectional shape of a cast-metal article to be cast as the molten metal passes through the shape defining member; and a pressurization device that applies a pressure to the molten metal held in the holding furnace and thereby makes the molten metal pass through the shape defining member. As a result, since a cast-metal article can be cast without using a starter, the productivity of cast-metal articles can be improved.
The pressurization device preferably applies a pressure to the molten metal held in the holding furnace by moving the shape defining member into the molten metal held in the holding furnace.
The pressurization device preferably includes an enclosed vessel that hermetically encloses the molten metal held in the holding furnace, and a pressurization unit that feeds a fluid into the enclosed vessel and thereby applies a pressure to the molten metal held in the holding furnace.
The pressurization device preferably further includes a stalk extending from the shape defining member to the molten-metal surface of the molten metal held in the holding furnace, and the pressurization device preferably applies a pressure to the molten metal held in the holding furnace and thereby makes the molten metal pass through the stalk and the shape defining member.
The pulling-up-type continuous casting apparatus preferably further includes a drawing section that grasps and pulls up the cast-metal article and thereby draws the molten metal held in the holding furnace through the shape defining member, the cast-metal article being formed as the molten metal that has passed through the shape defining member solidifies.
A pulling-up-type continuous casting method according to an aspect of the present invention includes: disposing a shape defining member in a vicinity of a molten-metal surface of molten metal held in a holding furnace, the shape defining member being configured to define a cross-sectional shape of a cast-metal article to be cast as the molten metal passes through the shape defining member; and applying a pressure to the molten metal held in the holding furnace and thereby making the molten metal pass through the shape defining member. As a result, since a cast-metal article can be cast without using a starter, the productivity of cast-metal articles can be improved.
It is preferable to apply a pressure to the molten metal held in the holding furnace by moving the shape defining member into the molten metal held in the holding furnace.
The pulling-up-type continuous casting method preferably further includes an enclosed vessel that hermetically encloses the molten metal held in the holding furnace, and the pressure is preferably applied to the molten metal held in the holding furnace by feeding a fluid into the enclosed vessel.
The pulling-up-type continuous casting method preferably further includes a stalk extending from the shape defining member to the molten-metal surface of the molten metal held in the holding furnace, and the molten metal is preferably made to pass through the stalk and the shape defining member by applying a pressure to the molten metal held in the holding furnace.
The pulling-up-type continuous casting method preferably further includes grasping and pulling up the cast-metal article and thereby drawing the molten metal held in the holding furnace through the shape defining member, the cast-metal article being formed as the molten metal that has passed through the shape defining member solidifies.

Advantageous Effects of Invention

According to the present invention, it is possible to provide a pulling-up-type continuous casting apparatus and a pulling-up-type continuous casting method capable of improving the productivity of cast-metal articles by applying a pressure to molten metal and thereby making the molten metal pass through a shape defining member without using a starter.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a cross section showing a configuration example of a free casting apparatus according to a first exemplary embodiment;

FIG. 2 is a plane view of a shape defining member 102 provided in the free casting apparatus shown in FIG. 1;

FIG. 3A is a figure for explaining an operation of a free casting apparatus according to a first exemplary embodiment;

FIG. 3B is a figure for explaining an operation of the free casting apparatus according to the first exemplary embodiment;

FIG. 3C is a figure for explaining an operation of the free casting apparatus according to the first exemplary embodiment;

FIG. 3D is a figure for explaining an operation of the free casting apparatus according to the first exemplary embodiment;

FIG. 3E is a figure for explaining an operation of the free casting apparatus according to the first exemplary embodiment;

FIG. 4 is a cross section showing a configuration example of a free casting apparatus according to a second exemplary embodiment;

FIG. 5 is a cross section showing a configuration example of a free casting apparatus according to a third exemplary embodiment;

FIG. 6 is a cross section showing another configuration example of a free casting apparatus according to the present invention; and

FIG. 7 is a plane view of a shape defining member 102 provided in the free casting apparatus shown in FIG. 6.

DESCRIPTION OF EMBODIMENTS

Specific exemplary embodiments to which the present invention is applied are explained hereinafter in detail with reference to the drawings. However, the present invention is not limited to exemplary embodiments shown below. Further, the following descriptions and the drawings are simplified as appropriate for clarifying the explanation.

First Exemplary Embodiment

Firstly, a free casting apparatus (pulling-up-type continuous casting apparatus) according to a first exemplary embodiment is explained with reference to FIG. 1. FIG. 1 is a cross section showing a configuration example of a free casting apparatus according to the first exemplary embodiment. As shown in FIG. 1, the free casting apparatus according to the first exemplary embodiment includes a molten-metal holding furnace (holding furnace) 101, an outer-shape defining member 102 a, a support rod 103, an actuator 104, a cooling nozzle (cooling unit) 105, and a drawing section 106.
The molten-metal holding furnace 101 contains molten metal M1 such as aluminum or its alloy, and maintains the molten metal M1 at a predetermined temperature. In the example shown in FIG. 1, since the molten-metal holding furnace 101 is not replenished with molten metal M1 during the casting process, the surface of molten metal M1 (i.e., molten-metal surface) is lowered as the casting process advances. Alternatively, the molten-metal holding furnace 101 may be replenished with molten metal as required during the casting process so that the molten-metal surface is kept at a fixed level. Needless to say, the molten metal M1 may be a metal other than aluminum or an alloy thereof.
The outer-shape defining member 102 a is made of ceramic or stainless, for example, and disposed in the vicinity of the molten-metal surface. In the example shown in FIG. 1, the outer-shape defining member 102 a is positioned in a place lower than the molten-metal surface. Further, in the example shown in FIG. 1, a sidewall W that extends vertically upward from the outer edge of the outer-shape defining member 102 a is integrally formed with the outer-shape defining member 102 a in order to prevent the molten metal M1 from flowing over the outer edge of the outer-shape defining member 102 a into the upper main surface thereof.
The outer-shape defining member 102 a defines the outer shape of a cast metal M3 to be cast. The cast metal M3 shown in FIG. 1 is a cylindrical solid cast-metal article having a circular shape in a horizontal cross section (hereinafter referred to as “lateral cross section”). That is, more specifically, the outer-shape defining member 102 a defines the outer diameter on the lateral cross section of the cast metal M3.
FIG. 2 is a plane view of the outer-shape defining member 102 a. Note that the cross section of the outer-shape defining member 102 a shown in FIG. 1 corresponds to a cross section taken along the line I-I in FIG. 2. As shown in FIG. 2, the outer-shape defining member 102 a has, for example, a rectangular shape as viewed from the top, and has a circular opening at the center. This opening serves as a molten-metal passage section 102 b through which molten metal passes. In this manner, the outer-shape defining member 102 a and the molten-metal passage section 102 b constitute a shape defining member 102.
The support rod 103 supports the outer-shape defining member 102 a. Note that the support rod 103 is connected to the actuator 104.
The actuator 104 has a function of moving the outer-shape defining member 102 a in the up/down direction (vertical direction) and in the horizontal direction through the support rod 103. In this manner, it is possible to move the outer-shape defining member 102 a downward as the molten-metal surface is lowered due to the advance of the casting process. Further, since the outer-shape defining member 102 a can be moved in the horizontal direction, the shape in the longitudinal direction of the cast metal M3 can be freely changed.
In the example shown in FIG. 1, the actuator 104 also has a function as a pressurization device that applies a pressure to the molten metal M1. Specifically, the actuator 104 moves the outer-shape defining member 102 a into the molten metal M1 (downward) and thereby applies a pressure to the molten metal M1. Then, when the outer-shape defining member 102 a moves to a position lower than the molten-metal surface of the molten metal M1, the molten metal M1 is pushed up from the molten-metal surface through the molten-metal passage section 102 b (the molten metal M1 passes through the molten-metal passage section 102 b). Note that the part of the molten metal M1 that is pushed up from the molten-metal surface by applying a pressure to the molten metal M1 (or pulled up by the drawing section 106 after that) but has not solidified yet is called “held molten metal M2”. Further, the interface between the held molten metal M2 and the cast metal M3, which is formed as the held molten metal M2 solidifies, is called “solidification interface”.
The cooling nozzle 105 sprays a cooling gas (such as air, nitrogen, and argon) on the held molten metal M2 that has passed through the molten-metal passage section 102 b and/or the cast metal M3 that is formed as the held molten metal M2 solidifies, and thereby cools the held molten metal M2 and/or the cast metal M3. The held molten metal M2, which has been made to pass through the molten-metal passage section 102 b by applying a pressure to the molten metal M1, is cooled by the cooling gas and solidifies, thus forming the cast metal M3.
The drawing section 106 includes a grasping section 1061, a connecting member 1062, and a pulling-up machine 1063. The grasping section 1061 grasps the cast metal M3 that is formed as the held molten metal M2 that has passed through the molten-metal passage section 102 b solidifies. The connecting member 1062 connects the grasping section 1061 with the pulling-up machine 1063. The pulling-up machine 1063 drives the grasping section 1061 in the up/down direction (vertical direction).
As the drawing section 106 pulls up the cast metal M3 that is formed as the held molten metal M2 solidifies, the molten metal M1 follows the pulled-up cast metal M3 and is also pulled up. As a result, the molten metal M1 passes through the molten-metal passage section 102 b as the held molten metal M2.
As described above, the free casting apparatus according to this exemplary embodiment makes the held molten metal M2 pass through the molten-metal passage section 102 b by applying a pressure to the molten metal M1. Further, the free casting apparatus according to this exemplary embodiment grasps and pulls up the cast metal M3 that is formed as the held molten metal M2 that has passed through the molten-metal passage section 102 b solidifies, and thereby also pulls up the molten metal M1 that follows the pulled up cast metal M3. That is, the free casting apparatus according to this exemplary embodiment uses the cast metal M3, which is formed as the held molten metal M2 solidifies, as a substitute for the starter. As a result, the free casting apparatus according to this exemplary embodiment can eliminate the need for replacing the starter every time a new cast-metal article is cast, thereby making it possible to reduce the time necessary for the replacement of the starter and reduce the cost. That is, the free casting apparatus according to this exemplary embodiment can improve the productivity of cast-metal articles.
Next, a free casting method according to this exemplary embodiment is explained with reference to FIGS. 1, 2 and 3A-3E. FIGS. 3A to 3E are figures for explaining an operation of a free casting apparatus according to the first exemplary embodiment.
Firstly, the outer-shape defining member 102 a is disposed in the vicinity of the molten-metal surface of the molten metal M1 held in the molten-metal holding furnace 101 (FIG. 3A).
Next, a pressure is applied to the the molten metal M1 by moving the outer-shape defining member 102 a into the molten metal M1 (FIG. 3B). As the outer-shape defining member 102 a moves to a place lower than the molten-metal surface of the molten metal M1, the molten metal M1 passes through the molten-metal passage section 102 b as held molten metal M2.
Next, the held molten metal M2 that has passed through the molten-metal passage section 102 b is cooled by a cooling gas sprayed from the cooling nozzle 105. As a result, the held molten metal M2 solidifies and forms cast metal M3 (FIG. 3C).
By further moving the outer-shape defining member 102 a into the molten metal M1 and cooling the held molten metal M2 that has passed through the molten-metal passage section 102 b, the cast metal M3 grows (FIG. 3D). Then, when the cast metal M3 grows to such a length that the grasping section 1061 can grasp the cast metal M3, the movement of the outer-shape defining member 102 a into the molten metal M1 is stopped (that is, the application of a pressure to the molten metal M1 is stopped). After that, the outer-shape defining member 102 a may be kept in the molten metal M1 or may be moved to the vicinity of the molten-metal surface of the molten metal M1. Note that when the outer-shape defining member 102 a is kept in the molten metal M1, the molten metal M1 is continuously kept in a pressurized state. Therefore, the drawn-up property of the molten metal M1 improves.
Next, the cast metal M3 is pulled up by the drawing section 106 (FIG. 3E). Note that even when the cast metal M3 is pulled away from the molten-metal surface, the molten metal M1 follows the cast metal M3 and is pulled up from the molten-metal surface by the surface film and/or the surface tension. The pulled-up molten metal M1 forms held molten metal M2. As shown in FIG. 1, the held molten metal M2 is formed in the molten-metal passage section 102 b. In other words, the held molten metal M2 is shaped into a given shape by the outer-shape defining member 102 a.
The held molten metal M2 that has pulled up by the drawing section 106 is cooled by a cooling gas sprayed from the cooling nozzle 105. As a result, the held molten metal M2 that has pulled up by the drawing section 106 successively solidifies from its upper side toward its lower side and hence the cast metal M3 grows. In this manner, it is possible to continuously cast the cast metal M3.
As described above, the free casting apparatus according to this exemplary embodiment makes the held molten metal M2 pass through the molten-metal passage section 102 b by applying a pressure to the molten metal M1. Further, the free casting apparatus according to this exemplary embodiment grasps and pulls up the cast metal M3 that is formed as the held molten metal M2 that has passed through the molten-metal passage section 102 b solidifies, and thereby pulls up the molten metal M1 that follows the pulled up cast metal M3. That is, the free casting apparatus according to this exemplary embodiment uses the cast metal M3 that is formed as the held molten metal M2 solidifies as a substitute for the starter. As a result, the free casting apparatus according to this exemplary embodiment can eliminate the need for replacing the starter every time a new cast-metal article is cast, thereby making it possible to reduce the time necessary for the replacement of the starter and reduce the cost. That is, the free casting apparatus according to this exemplary embodiment can improve the productivity of cast-metal articles.

Second Exemplary Embodiment

FIG. 4 is a cross section showing a configuration example of a free casting apparatus according to a second exemplary embodiment. The free casting apparatus shown in FIG. 4 includes a pressurization device having a configuration different from that of the pressurization device of the free casting apparatus shown in FIG. 1.
Specifically, in comparison to the free casting apparatus shown in FIG. 1, the free casting apparatus shown in FIG. 4 further includes a lid 107 for hermetically enclosing the molten metal M1 and a fluid supply unit (pressurization unit) 108 that feeds a fluid into the hermetically enclosed area. Further, in the example shown in FIG. 4, a tubular stalk S that extends from the inner edge of the outer-shape defining member 102 a (that is, from the molten-metal passage section 102 b ) to the molten-metal surface of the molten metal M1. Note that in the example shown in FIG. 4, the sidewall W that extends vertically upward from the outer edge of the outer-shape defining member 102 a does not have to be provided because no molten metal M1 flows over the outer edge of the outer-shape defining member 102 a into the upper main surface thereof. The other configuration of the free casting apparatus shown in FIG. 4 is similar to that of the free casting apparatus shown in FIG. 1, and therefore its explanation is omitted.
The lid 107 closes the opened section of the molten metal holding furnace 101. That is, the molten metal holding furnace 101 and the lid 107 constitute an enclosed vessel that hermetically encloses the molten metal M1. However, the lid 107 includes an opened section having such a size that the stalk S can pass through the opened section. The stalk S extends from the inner edge of the outer-shape defining member 102 a (that is, from the molten-metal passage section 102 b) to the molten-metal surface of the molten metal M1 through the opened section.
The fluid supply unit 108 applies a pressure to the molten metal M1 by feeding a fluid such as atmospheric air into the enclosed vessel. As a result, the molten metal M1 passes through the stalk S and the molten-metal passage section 102 b. Therefore, the free casting apparatus shown in FIG. 4 can produce advantageous effects equivalent to those of the free casting apparatus shown in FIG. 1.

Third Exemplary Embodiment

FIG. 5 is a cross section showing a configuration example of a free casting apparatus according to a third exemplary embodiment. The free casting apparatus shown in FIG. 5 includes a pressurization device having a configuration different from that of the pressurization device of the free casting apparatus shown in FIG. 1.
Specifically, in comparison to the free casting apparatus shown in FIG. 1, the free casting apparatus shown in FIG. 5 further includes an object 109 and a drive unit 110 that drives the object 109 in the up/down direction (vertical direction). The other configuration of the free casting apparatus shown in FIG. 5 is similar to that of the free casting apparatus shown in FIG. 1, and therefore its explanation is omitted.
The object 109 is formed of material having a melting point higher than that of the molten metal M1. The drive unit 110 moves the object 109 from outside of the molten metal M1 into the molten metal M1 and thereby applies a pressure to the molten metal M1. As a result, the free casting apparatus shown in FIG. 5 can produce advantageous effects equivalent to those of the free casting apparatus shown in FIG. 1.
As described above, the free casting apparatuses according to the above-described first to third exemplary embodiments apply a pressure to the the molten metal M1 and thereby make the molten metal M1 pass through the shape defining member 102 without using a starter. As a result, the free casting apparatuses according to the first to third exemplary embodiments can eliminate the need for replacing the starter every time a new cast-metal article is cast, thereby making it possible to reduce the time necessary for the replacement of the starter and reduce the cost. That is, the free casting apparatuses according to the first to third exemplary embodiments can improve the productivity of cast-metal articles.
Although example cases where a cast-metal article having a cylindrical shape (cylindrical cast-metal article) is cast are explained in the above-described exemplary embodiments, the present invention is not limited to such examples. The present invention can also be applied to cases where a cast-metal article having a tubular shape, a square pillar shape, a square tubular shape, or other shapes is cast. A case where a cast-metal article having a tubular shape is cast is briefly explained hereinafter with reference to FIGS. 6 and 7.
FIG. 6 is a cross section showing another configuration example of a free casting apparatus according to the present invention. The free casting apparatus shown in FIG. 6 includes an inner-shape defining member 102 c in addition to the outer-shape defining member 102 a.
The inner-shape defining member 102 c defines the inner shape of a cast metal M3 to be cast and the outer-shape defining member 102 a defines the outer shape of the cast metal M3 to be cast. The cast metal M3 shown in FIG. 6 is a hollow cast-metal article having a ring shape in a horizontal cross section (hereinafter referred to as “lateral cross section”) (that is, the cast metal M3 shown in FIG. 6 is a pipe). That is, more specifically, the inner-shape defining member 102 c defines the inner diameter on the lateral cross section of the cast metal M3 and the outer-shape defining member 102 a defines the outer diameter on the lateral cross section of the cast metal M3.
The inner-shape defining member 102 c is supported by a support rod 111. The support rod 111 is connected to the actuator 104. The actuator 104 has a function of moving the outer-shape defining member 102 a and the inner-shape defining member 102 c in the up/down direction (vertical direction) and in the horizontal direction through the support rods 103 and 111, respectively.
FIG. 7 is a plane view of the inner-shape defining member 102 c and the outer-shape defining member 102 a. Note that the cross section of the inner-shape defining member 102 c and the outer-shape defining member 102 a in FIG. 6 corresponds to a cross section taken along the line II-II in FIG. 7. As shown in FIG. 7, the outer-shape defining member 102 a has, for example, a rectangular shape as viewed from the top, and has a circular opening at the center. The inner-shape defining member 102 c has a circular shape as viewed from the top and is disposed at the center of the opening of the outer-shape defining member 102 a. The gap between the inner-shape defining member 102 c and the outer-shape defining member 102 a serves as the molten-metal passage section 102 b through which the molten metal passes. In this manner, the inner-shape defining member 102 c, the outer-shape defining member 102 a, and the molten-metal passage section 102 b constitute a shape defining member 102. With this configuration, a cast-metal article having a tubular shape is cast.
Note that the present invention is not limited to the above-described exemplary embodiments, and various modifications can be made without departing the spirit and scope of the present invention. For example, the above-described configuration examples may be combined and used at the same time.
This application is based upon and claims the benefit of priority from Japanese patent application No. 2013-236639, filed on Nov. 15, 2013, the disclosure of which is incorporated herein in its entirety by reference.

REFERENCE SIGNS LIST

101 MOLTEN METAL HOLDING FURNACE
102 SHAPE DEFINING MEMBER
102 a OUTER-SHAPE DEFINING MEMBER
102 b MOLTEN-METAL PASSAGE SECTION
102 c INNER-SHAPE DEFINING MEMBER
103 SUPPORT ROD
104 ACTUATOR
105 COOLING NOZZLE
1061 GRASPING SECTION
1062 CONNECTING MEMBER
1063 PULLING-UP MACHINE
106 DRAWING SECTION
107 LID
108 FLUID SUPPLY UNIT
109 OBJECT
110 DRIVE UNIT
111 SUPPORT ROD
M1 MOLTEN METAL
M2 HELD MOLTEN METAL
M3 CAST METAL
W SIDEWALL
S STALK

Claims

1. A pulling-up-type continuous casting apparatus comprising:

a holding furnace that holds molten metal;

a shape defining member disposed in a vicinity of a molten-metal surface of the molten metal, the shape defining member being configured to define a cross-sectional shape of a cast-metal article to be cast as the molten metal passes through the shape defining member; and

a pressurization device that applies a pressure to the molten metal held in the holding furnace and thereby makes the molten metal pass through the shape defining member.

2. The pulling-up-type continuous casting apparatus according to claim 1, wherein the pressurization device applies a pressure to the molten metal held in the holding furnace by moving the shape defining member into the molten metal held in the holding furnace.

3. The pulling-up-type continuous casting apparatus according to claim 1, wherein the pressurization device comprises:

an enclosed vessel that hermetically encloses the molten metal held in the holding furnace; and

a pressurization unit that feeds a fluid into the enclosed vessel and thereby applies a pressure to the molten metal held in the holding furnace.

4. The pulling-up-type continuous casting apparatus according to claim 3, wherein

the pressurization device further comprises a stalk extending from the shape defining member to the molten-metal surface of the molten metal held in the holding furnace, and

the pressurization device applies a pressure to the molten metal held in the holding furnace and thereby makes the molten metal pass through the stalk and the shape defining member.

5. The pulling-up-type continuous casting apparatus according to claim 1, further comprising a drawing section that grasps and pulls up the cast-metal article and thereby draws the molten metal held in the holding furnace through the shape defining member, the cast-metal article being formed as the molten metal that has passed through the shape defining member solidifies.

6. A pulling-up-type continuous casting method comprising:

disposing a shape defining member in a vicinity of a molten-metal surface of molten metal held in a holding furnace, the shape defining member being configured to define a cross-sectional shape of a cast-metal article to be cast as the molten metal passes through the shape defining member; and

applying a pressure to the molten metal held in the holding furnace and thereby making the molten metal pass through the shape defining member.

7. The pulling-up-type continuous casting method according to claim 6, wherein a pressure is applied to the molten metal held in the holding furnace by moving the shape defining member into the molten metal held in the holding furnace.

8. The pulling-up-type continuous casting method according to claim 6, further comprising an enclosed vessel that hermetically encloses the molten metal held in the holding furnace,

wherein the pressure is applied to the molten metal held in the holding furnace by feeding a fluid into the enclosed vessel.

9. The pulling-up-type continuous casting method according to claim 8, further comprising a stalk extending from the shape defining member to the molten-metal surface of the molten metal held in the holding furnace, and

the molten metal is made to pass through the stalk and the shape defining member by applying a pressure to the molten metal held in the holding furnace.

10. The pulling-up-type continuous casting method according to claim 6, further comprising grasping and pulling up the cast-metal article and thereby drawing the molten metal held in the holding furnace through the shape defining member, the cast-metal article being formed as the molten metal that has passed through the shape defining member solidifies.