1. Field of the Invention
The present invention relates to an up-drawing continuous casting apparatus and an up-drawing continuous casting method.
2. Description of Related Art
Japanese Patent Application Publication No. 2012-61518 (JP 2012-61518 A) proposes a free casting method as an epoch-making up-drawing continuous casting method that does not require a mold. As described in JP 2012-61518 A, when a starter is immersed into a surface of molten metal (that is, a molten metal surface) and then the starter is drawn up, the molten metal is also led out following the starter due to a surface film and a surface tension of the molten metal. Here, a casting having a desired sectional shape can be continuously casted by leading out the molten metal via a shape determining member placed near the molten metal surface, and then cooling the molten metal thus led out.
With a normal continuous casting method, the sectional shape and the shape in a longitudinal direction are both determined by a mold. Particularly, in the continuous casting method, solidified metal (i.e., a casting) should pass through a mold, so that a casting casted hereby has a shape that extends linearly in the longitudinal direction. In the meantime, the shape determining member in the free casting method determines only the sectional shape of the casting and does not determine the longitudinal shape thereof. On that account, castings having various longitudinal shapes can be obtained by drawing up the starter while moving the starter (or the shape determining member) horizontally. For example, JP 2012-61518 A describes a hollow casting (that is, a pipe) formed not in a linear shape in its longitudinal direction, but in a zigzag shape or a helical shape in the longitudinal direction. Here, a free casting apparatus described in JP 2012-61518 A can change the sectional shape of the casting by moving the shape determining member.
The inventor(s) found the following problem. JP 2012-61518 A describes that the sectional shape of the casting is changed by moving the shape determining member as described above, but does not describe how the shape determining member is moved at that time. If the shape determining member is deformed so that some parts of the shape determining member are distanced from each other, the sectional shape of the casting cannot be determined in that distanced part. Further, even if a plurality of shape determining members is put on top of one another in advance and the plurality of shape determining members is moved relative to each other within a range where they are put on top of one another, there is a possibility that their moving ranges are limited. That is, the free casting method described in JP 2012-61518 A has a possibility that a degree of freedom of the sectional shape of the casting cannot be improved.
The present invention provides an up-drawing continuous casting apparatus and an up-drawing continuous casting method each of which can improve a degree of freedom of a sectional shape of a casting.
An up-drawing continuous casting apparatus according to one aspect of the present invention is an up-drawing continuous casting apparatus including: a holding furnace configured to hold molten metal; and a shape determining member placed on a molten metal surface of the molten metal and configured to determine a sectional shape of a casting to be casted when the molten metal led out from the molten metal surface passes through the shape determining member. The shape determining member includes a first partial shape determining member and a second partial shape determining member connectable to each other, and a connecting member configured to connect the first partial shape determining member to the second partial shape determining member. When the first partial shape determining member and the second partial shape determining member are distanced from each other, the sectional shape of the casting to be casted is determined by the first partial shape determining member, the second partial shape determining member, and the connecting member. Hereby, the sectional shape of the casting can be determined with a distanced part being compensated by the connecting member, thereby making it possible to improve a degree of freedom of the sectional shape of the casting.
The connecting member may be a wire or a tape. This makes it possible to achieve downsizing of the shape determining member.
The up-drawing continuous casting apparatus may further include a bobbin around which the wire or the tape is wound. This makes it possible to use the wire stored in the bobbin by drawing out the wire only by a necessary length, thereby making it possible to further improve the degree of freedom of the sectional shape of the casting.
The up-drawing continuous casting apparatus may further include a driving portion configured to rotate the bobbin so as to increase a tensile force of the wire or the tape. Hereby, the wire is restrained from being loose, thereby making it possible to prevent the wire from being drawn up together when the molten metal is drawn up.
The up-drawing continuous casting apparatus may further include an elastic member configured to give a tensile force to the wire or the tape. Hereby, the wire is restrained from being loose, thereby making it possible to prevent the wire from being drawn up together when the molten metal is drawn up.
The connecting member may be a plate.
The connecting member may be an inner shape determining plate.
The connecting member may be a plurality of plate materials slidable in a horizontal direction.
The connecting member may be a plate material having a bellows shape.
The up-drawing continuous casting apparatus may be configured such that: when the starter is immersed into the molten metal surface of the molten metal and then the starter is drawn up, the molten metal follows the starter due to a surface film and a surface tension of the molten metal and the molten metal is led out; the molten metal is led out via the shape determining member provided near the molten metal surface; and the molten metal is cooled off so as to continuously cast the casting having a desired sectional shape.
An up-drawing continuous casting method according to one aspect of the present invention is an up-drawing continuous casting method for casting a casting such that molten metal is led out from a molten metal surface of the molten metal held in a holding furnace and is passed through a shape determining member configured to determine a sectional shape of the casting, and is configured to determine the sectional shape of the casting to be casted, by a first partial shape determining member, a second partial shape determining member, and a connecting member when the first partial shape determining member and the second partial shape determining member are distanced from each other, the first partial shape determining member and the second partial shape determining member being connectable to each other, the connecting member being configured to connect the first partial shape determining member to the second partial shape determining member. Hereby, the sectional shape of the casting can be determined with a distanced part being compensated by the connecting member, thereby making it possible to improve a degree of freedom of the sectional shape of the casting.
According to the present invention, it is possible to provide an up-drawing continuous casting apparatus and an up-drawing continuous casting method each of which can improve a degree of freedom of a sectional shape of a casting.
Features, advantages, and technical and industrial significance of exemplary embodiments of the invention will be described below with reference to the accompanying drawings, in which like numerals denote like elements, and wherein:
The following describes concrete embodiments to which the present invention is applied with reference to the drawings. However, the present invention is not limited to the following embodiments. Further, the following description and drawings are simplified appropriately for clarification of the description.
First described is a free casting apparatus (an up-drawing continuous casting apparatus) according to Embodiment 1, with reference to
The molten metal holding furnace 101 stores therein molten metal M1 of aluminum or its alloy, for example, and keeps the molten metal M1 at a predetermined temperature (e.g., around 720° C.) at which the molten metal M1 has fluidity. In the example in
The shape determining member 102 is made of ceramics or stainless, for example, and is placed on the molten metal M1. The shape determining member 102 includes an outer shape determining member 103 and an inner shape determining member 104. The outer shape determining member 103 determines an outer sectional shape of a casting M3 to be casted, and the inner shape determining member 104 determines an inner sectional shape of the casting M3 to be casted. The casting M3 illustrated in
In the example illustrated in
As illustrated in
Further, as illustrated in
Note that, in this example, the inner shape determining plate 1043 is placed so that, in a plan view, a top side thereof is placed on the same straight line as top sides of the inner shape determining plates 1041, 1042, and a bottom side thereof is placed on the same straight line as bottom sides of the inner shape determining plates 1041, 1042. However, the flat shape and a placement position of the inner shape determining plate 1043 are modifiable appropriately depending on an inner sectional shape of the casting M3.
Here, the inner shape determining plates 1041, 1042 are independently movable (connectable and disconnectable) in the x-axis direction. Further, the inner shape determining plate 1043 is also movable in the x-axis direction over the inner shape determining plates 1041, 1042. For example, a slider extending in the x-axis direction is provided on a bottom face of the inner shape determining plate 1043, and rails extending in the x-axis direction and guiding the slider are provided on top faces of the inner shape determining plates 1041, 1042, so that the inner shape determining plate 1043 is slidable in the x-axis direction over the inner shape determining plates 1041, 1042. Note that moving ranges of the inner shape determining plates 1041 to 1043 are within a range where a distanced part (a space SP) between the inner shape determining plates 1041, 1042 is covered with the inner shape determining plate 1043 at the time when the inner shape determining plates 1041, 1042 are distanced from each other.
A gap between the outer shape determining member 103 and the inner shape determining member 104 serves as a molten metal passage portion 105 through which the molten metal passes.
In the example of
Referring now to
As illustrated in
The inner shape determining plate 1043 determines part of the inner sectional shape of the casting M3 so as to compensate a part corresponding to the space SP. That is, when the inner shape determining plates 1041, 1042 are distanced from each other to form the space SP, the inner sectional shape of the casting M3 is determined by the inner shape determining plates 1041, 1042, and the inner shape determining plate 1043. In the example of
Now referring back to
As illustrated in
The starter ST is made of ceramics or stainless, for example. Note that a surface of the starter ST may be covered with a protective surface film of salt crystals or the like. Hereby, a molten connection between the starter ST and the molten metal M1 is restrained, thereby making it possible to improve releasability between the starter ST and the casting M3. This allows the starter ST to be reused. Further, in a case where the surface of the starter ST is covered with the protective surface film, it is preferable that the surface of the starter ST have an irregular shape. This causes the protective surface film to be easily attached (deposited) onto the surface of the starter ST, thereby making it possible to further improve the releasability between the starter ST and the casting M3. At the same time, it is possible to improve cohesive strength between the starter ST and the molten metal M1 in a draw-up direction at the time of leading out the molten metal.
The support rod 106 supports the outer shape determining member 103, and the support rod 107 supports the inner shape determining member 104. Here, if the support rod 107 has a pipe structure so that coolant gas is flowed therethrough, and further, a jetting hole is provided in the inner shape determining member 104, the casting M3 can be cooled off from its inside.
The support rods 106, 107 are both connected to the actuator 108. The actuator 108 can move the outer shape determining member 103 and the inner shape determining member 104 in an up-down direction (the z-axis direction) via the support rods 106, 107. This makes it possible to move the shape determining member 102 downward when the casting proceeds and the molten metal surface drops.
Further, the actuator 108 can move the outer shape determining member 103 and the inner shape determining member 104 in a horizontal direction (the x-axis direction and the y-axis direction) via the support rods 106, 107. This makes it possible to change the longitudinal shape of the casting M3 freely. Here, the actuator 108 can independently move the outer shape determining plates 1031, 1032 and the inner shape determining plates 1041 to 1043, as described above. This makes it possible to change the sectional shape of the casting M3 freely.
The coolant gas nozzle 109 cools off the starter ST and the casting M3 by spraying coolant gas (air, nitrogen, argon, or the like) thereon. When a flow rate of the coolant gas is increased, the position of the solidification interface SIF is lowered, and when the flow rate of the coolant gas is decreased, the position of the solidification interface SIF is raised. Note that the coolant gas nozzle 109 is also movable in the up-down direction (the z-axis direction) and in the horizontal direction (the x-axis direction and the y-axis direction). Accordingly, the coolant gas nozzle 109 can be moved downward along with downward movement of the shape determining member 102 when the casting proceeds and the molten metal surface drops, for example. Alternatively, the coolant gas nozzle 109 can be moved in the horizontal direction along with horizontal movement of the draw-up machine 110 and the shape determining member 102.
When the starter ST or the casting M3 is cooled off by the coolant gas with the casting M3 being drawn up by the draw-up machine 110 connected to the starter ST, the retained molten metal M2 near the solidification interface SIF solidifies sequentially from an upper side (a positive side in the z-axis direction) to a lower side (a negative side in the z-axis direction), and thus, the casting M3 is formed. When a draw-up speed by the draw-up machine 110 is increased, the position of the solidification interface SIF can be raised. When the draw-up speed is decreased, the position of the solidification interface SIF can be lowered. Further, it is possible to freely change the longitudinal shape of the casting M3 by drawing up the casting M3 with the draw-up machine 110 being moved in the horizontal direction (in the x-axis direction and the y-axis direction), similarly to a case where the shape determining member 102 is moved in the horizontal direction.
With reference to
Initially, a tip end (a lower end) of the starter ST is immersed into the molten metal M1 by moving the starter ST1 downward by the draw-up machine 110 so as to pass the starter ST through the molten metal passage portion 105 between the outer shape determining member 103 and the inner shape determining member 104.
Then, the starter ST is drawn up at a predetermined speed. Here, even if the starter ST is distanced from the molten metal surface, the molten metal M1 is drawn up (led out), from the molten metal surface, following the starter ST due to its surface film and surface tension, so that the retained molten metal M2 is formed. As illustrated in
Then, the starter ST and the casting M3 are cooled off by the coolant gas sprayed from the coolant gas nozzle 109. Hereby, the retained molten metal M2 is cooled off indirectly and solidifies sequentially from the upper side to the lower side, so that the casting M3 grows. Thus, the casting M3 can be casted continuously.
Here, in a case where the sectional shape of the casting M3 is enlarged in the x-axis direction, the outer shape determining plates 1031, 1032 are moved toward the negative side and the positive side in the x-axis direction, respectively, and the inner shape determining plates 1041, 1042 are moved toward the negative side and the positive side in the x-axis direction, respectively. Hereby, the space SP is formed between the inner shape determining plates 1041, 1042. However, at this time, the inner shape determining plate 1043 is placed to cover the space SP. The inner shape determining plate 1043 determines part of the inner sectional shape of the casting M3 so as to compensate a part corresponding to the space SP. Hereby, the inner shape determining member 104 can give a desired sectional shape (a rectangular sectional shape enlarged in the x-axis direction in this example) to the casting M3 without suffering a loss of part of the sectional shape of the casting M3 due to the space SP.
Thus, in the free casting apparatus according to the present embodiment, when the inner shape determining plates 1041, 1042 are distanced from each other to form the space SP, the sectional shape of the casting M3 is determined by the inner shape determining plates 1041, 1042, and the inner shape determining plate 1043 as a connecting member. Hereby, in the free casting apparatus according to the present embodiment, a desired sectional shape can be given to the casting M3 without suffering a loss of part of the sectional shape of the casting M3 due to the space SP. That is, the free casting apparatus according to the present embodiment can improve a degree of freedom of the sectional shape of the casting M3.
A free casting apparatus according to Embodiment 2 includes a shape determining member 102 having a different structure from the free casting apparatus according to Embodiment 1.
In comparison with the shape determining member 102 illustrated in
The wires W1, W2 are made of a heat resisting material such as alumina fiber, or a metallic material having a high-melting point such as stainless. The wires W1, W2 may be a solid wire or a twisted wire, but the twisted wire is hard to cause raveling and winding curl.
As illustrated in
That is, in a plan view, the wire W1 is placed so as to extend in the x-axis direction from the bottom side of the inner shape determining plate 1041 to the bottom side of the inner shape determining plate 1042. Further, in a plan view, the wire W2 is placed so as to extend in the x-axis direction from the top side of the inner shape determining plate 1041 to the top side of the inner shape determining plate 1042. Note that, in this example, in a plan view, the wire W1 is placed on the same straight line as the bottom sides of the inner shape determining plates 1041, 1042. Further, in a plan view, the wire W2 is placed on the same straight line as the top sides of the inner shape determining plates 1041, 1042. However, placement positions of the wires W1, W2 are modifiable appropriately depending on an inner sectional shape of the casting M3.
Here, a driving portion configured to rotate the bobbins B1, B2 may be further provided so as to increase tensile forces of the wires W1, W2. Hereby, the wires W1, W2 are restrained from being loose, thereby making it possible to prevent the wires W1, W2 from being drawn up together when the molten metal M1 is drawn up.
In the example of
Subsequently, in the example of
The wires W1, W2 determine part of the inner sectional shape of the casting M3 so as to compensate a part corresponding to the space SP. That is, when the inner shape determining plates 1041, 1042 are distanced from each other to form the space SP, the inner sectional shape of the casting M3 is determined by the wires W1, W2, as well as the inner shape determining plates 1041, 1042. In the example of
Thus, in the free casting apparatus according to the present embodiment, when the inner shape determining plates 1041, 1042 are distanced from each other to form the space SP, the sectional shape of the casting M3 is determined by the wires W1, W2 as a connecting member, as well as the inner shape determining plates 1041, 1042. Hereby, in the free casting apparatus according to the present embodiment, a desired sectional shape can be given to the casting M3 without suffering a loss of part of the sectional shape of the casting M3 due to the space SP. That is, the free casting apparatus according to the present embodiment can improve a degree of freedom of the sectional shape of the casting M3.
Further, in the free casting apparatus according to the present embodiment, the wires W1, W2 are provided as a connecting member configured to connect the inner shape determining plates 1041, 1042, thereby making it possible to achieve downsizing of the shape determining member 102. Further, the bobbins B1, B2 are provided, so that the wires W1, W2 stored in the bobbins B1, B2 can be used by drawing out the wires W1, W2 only by a necessary length, thereby making it possible to further improve the degree of freedom of the sectional shape of the casting M3.
(First Modification of Shape Determining Member 102 According Embodiment 2)
As illustrated in
With such a configuration, the shape determining member 102 illustrated in
Note that the shape determining member 102 illustrated in
(Second Modification of Shape Determining Member 102 According Embodiment 2)
(Third Modification of Shape Determining Member 102 According Embodiment 2)
With such a configuration, the shape determining member 102 illustrated in
Note that, in the example of
Note that the first to third modifications of the shape determining member 102 may be used by combining some of them or all of them.
A free casting apparatus according to Embodiment 3 includes a shape determining member 102 having a different structure from the free casting apparatuses according to Embodiments 1, 2.
The shape determining member 102 illustrated in
The elastic members S1, S2 are springs, for example, and give tensile forces to wires W1, W2, respectively. With such a configuration, the wires W1, W2 are restrained from being loose, so it is possible to prevent the wires W1, W2 from being drawn up together when molten metal M1 is drawn up.
A free casting apparatus according to Embodiment 4 includes a shape determining member 102 having a different structure from the free casting apparatuses according to Embodiments 1 to 3.
The shape determining member 102 illustrated in
With such a configuration, the shape determining member 102 illustrated in
A free casting apparatus according to Embodiment 5 includes a shape determining member 102 having a different structure from the free casting apparatuses according to Embodiments 1 to 4.
The shape determining member 102 illustrated in
With such a configuration, the shape determining member 102 illustrated in
As described above, in the free casting apparatuses according to Embodiments 1 to 5, when the inner shape determining plates 1041, 1042 are distanced from each other to form the space SP, the sectional shape of the casting M3 is determined by the inner shape determining plates 1041, 1042, and the connecting member (the inner shape determining plate 1043, the wires W1, W2, the tapes T1, T2, or the like). Hereby, in the free casting apparatuses according to Embodiments 1 to 5, a desired sectional shape can be given to the casting M3 without suffering a loss of part of the sectional shape of the casting M3 due to the space SP. That is, the free casting apparatuses according to Embodiments 1 to 5 can improve the degree of freedom of the sectional shape of the casting M3.
Embodiments 1 to 5 deal with a case where the inner shape determining plates 1041, 1042 connectable to and disconnectable from each other, and the connecting member (the inner shape determining plate 1043, the wires W1, W2, the tapes T1, T2, or the like) configured to connect them are provided, but Embodiments 1 to 5 are not limited to this. First and second outer shape determining members connectable to and disconnectable from each other, and a connecting member configured to connect them may be provided. In such a configuration, when the first and second outer shape determining members make contact with each other, an outer sectional shape of a casting to be casted is determined only by the first and second outer shape determining members, and when the first and second outer shape determining members are distanced from each other, the outer sectional shape of the casting to be casted is determined by the first and second outer shape determining members and the connecting member.
Note that the present invention is not limited to the above embodiments, and various modifications can be made within a range that does not deviate from a gist of the present invention.
Number | Date | Country | Kind |
---|---|---|---|
2014-001755 | Jan 2014 | JP | national |
Filing Document | Filing Date | Country | Kind |
---|---|---|---|
PCT/IB2014/002851 | 12/22/2014 | WO | 00 |
Publishing Document | Publishing Date | Country | Kind |
---|---|---|---|
WO2015/104576 | 7/16/2015 | WO | A |
Number | Name | Date | Kind |
---|---|---|---|
20130171021 | Yaokawa et al. | Jul 2013 | A1 |
Number | Date | Country |
---|---|---|
63-199050 | Aug 1988 | JP |
2012-61518 | Mar 2012 | JP |
Entry |
---|
International Search Report Issued Apr. 24, 2015 in PCT/IB2014/002851 filed Dec. 22, 2014. |
Number | Date | Country | |
---|---|---|---|
20160325347 A1 | Nov 2016 | US |