JP2014144483A - Hoisting type continuous casting device and hoisting type continuous casting method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hoisting type continuous casting device and a hoisting type continuous casting method that can form a casting with a branching structure.SOLUTION: A hoisting type continuous casting device relating to one embodiment of the present invention includes a holding furnace 101 for holding a molten metal M1, and a shape defining member 102 installed in the vicinity of a bath surface of the molten metal M1 held in the holding furnace 101 and defining a cross-sectional shape of a casting M3 that is cast by the passing of the molten metal M1. The shape defining member 102 can switch between a bond state and split state. The formation of the casting having a branching structure is enabled with such a configuration.

Description

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

  In Patent Document 1, the inventors have proposed a free casting method as an innovative pulling-up-type continuous casting method that does not require a mold. As shown in Patent Document 1, after the starter is immersed in the surface of the molten metal (molten metal) (that is, the molten metal surface), when the starter is pulled up, the molten metal follows the starter by the surface film or surface tension of the molten metal. Derived. 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.

In a normal continuous casting method, the shape in the longitudinal direction is defined along with the cross-sectional shape by the mold. In particular, in the continuous casting method, since the solidified metal (that is, the casting) needs to pass through the mold, the cast casting has a shape extending linearly in the longitudinal direction.
On the other hand, the shape defining member in the free casting method defines only the cross-sectional shape of the casting, and does not define the shape in the longitudinal direction. And since a shape prescription | regulation member can move to the direction (namely, horizontal direction) parallel to a molten metal surface, the casting in which the shape of a longitudinal direction is various is obtained. For example, Patent Document 1 discloses a hollow casting (that is, a pipe) that is formed in a zigzag shape or a spiral shape instead of being linear in the longitudinal direction.

JP 2012-61518 A

The inventor has found the following problems.
Patent Document 1 does not disclose a method for manufacturing a casting having a branched structure.

  The present invention has been made in view of the above, and an object thereof is to provide an up-drawing continuous casting apparatus and an up-drawing continuous casting method capable of forming a casting having a branched structure.

The up-drawing continuous casting apparatus according to one aspect of the present invention is as follows.
A holding furnace for holding molten metal;
A shape defining member that is installed in the vicinity of the molten metal surface of the molten metal held in the holding furnace and that defines a cross-sectional shape of a casting to be cast by passing the molten metal;
The shape defining member can be switched between a coupled state and a divided state.
With such a configuration, it becomes possible to form a casting having a branched structure.

When the shape defining member is in a divided state, it is preferable to further include a molten cutter inserted into the molten metal that has passed through the shape defining member. Moreover, it is preferable that a pair of said molten metal cutters are opposingly arranged through the said molten metal which passed the said shape determination member on the dividing line where the said shape determination member is divided | segmented.
With such a configuration, a casting having a branched structure can be more reliably formed.

It is preferable that the shape defining member includes an internal shape defining member and an external shape defining member, and a cast product to be cast has a hollow structure.
Moreover, it is preferable to further include a cooling unit that cools and solidifies the molten metal that has passed through the shape defining member.

The up-drawing continuous casting method according to one aspect of the present invention is as follows.
A step of pulling the molten metal held in the holding furnace through a shape defining member that defines the cross-sectional shape of the casting to be cast; and
Cooling and solidifying the molten metal that has been pulled up through the shape determining member,
In the middle of casting, the shape defining member is switched from the coupled state to the divided state.
With such a configuration, it becomes possible to form a casting having a branched structure.
The shape defining member that has been divided during casting may be switched from the divided state to the coupled state.

When the shape defining member is in a divided state, it is preferable to insert a molten metal cutter into the molten metal that has passed through the shape defining member. In addition, it is preferable that the pair of molten metal cutters are arranged to face each other via the molten metal that has passed through the shape defining member on a dividing line where the shape defining member is divided.
With such a configuration, a casting having a branched structure can be more reliably formed.

  Further, it is preferable that the shape defining member is composed of an internal shape defining member and an external shape defining member, and a casting having a hollow structure is cast.

  ADVANTAGE OF THE INVENTION By this invention, the pulling-up-type continuous casting apparatus and pulling-up-type continuous casting method which can form the casting which has a branch structure can be provided.

1 is a cross-sectional view of a free casting apparatus according to Embodiment 1. FIG. FIG. 6 is a plan view of the shape defining member 102 (when coupled). It is a top view (at the time of a division | segmentation) of the shape prescription | regulation member 102. FIG. 5 is a plan view showing the positional relationship between the shape defining member 102 and the molten metal cutters C1 and C2 (when the shape defining member 102 is coupled). FIG. 5 is a plan view showing the positional relationship between the shape defining member 102 and the molten metal cutters C1 and C2 (when the shape defining member 102 is divided). 3 is a perspective view of a casting M3 according to Embodiment 1. FIG. It is a cross-sectional perspective view by the VV cutting line 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 of a free casting apparatus according to Embodiment 1. FIG. As shown in FIG. 1, the free casting apparatus according to Embodiment 1 includes a molten metal holding furnace 101, three internal shape defining members 102a1, 102a2, 102a3, an external shape defining member 102b, four internal cooling gas nozzles 103, and a support. A rod 104, an actuator 105, and an external cooling gas nozzle 106 are provided. 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 it at a predetermined temperature. 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. As a matter of course, the molten metal M1 may be another metal or alloy other than aluminum.

The internal shape defining members 102a1, 102a2, 102a3 and the external shape defining member 102b are made of, for example, ceramics or stainless steel, and are disposed in the vicinity of the molten metal surface. In the example of FIG. 1, three internal shape defining members 102a1, 102a2, 102a3 and one external shape defining member 102b are arranged so as to contact the molten metal surface. However, the inner shape defining members 102a1, 102a2, 102a3 and the outer shape defining member 102b may be installed such that their main surfaces on the lower side (the hot water surface side) do not contact the hot water surface. Specifically, a predetermined gap (for example, about 0.5 mm) may be provided between the main surface of the inner shape defining members 102a1, 102a2, 102a3 and the outer shape defining member 102b and the molten metal surface.
The three internal shape defining members 102a1, 102a2, and 102a3 define the internal shape of the casting M3 to be cast, and the external shape defining member 102b defines the external shape of the cast M3 to be cast.

  As shown in FIG. 1, the molten metal M1 is pulled up following the casting M3 by its surface film and surface tension, and passes through the molten metal passage portion 102c. Here, the molten metal pulled up from the molten metal surface following the casting M3 by the surface film or surface tension of the molten metal is referred to as a retained molten metal M2. Further, the interface between the casting M3 and the retained molten metal M2 is a solidification interface.

  Internal cooling gas nozzles 103 are connected to the central portions of the internal shape defining members 102a1 and 102a3, respectively. The internal shape defining member 102a2 divided into two has an internal cooling gas nozzle 103 connected to the center of each. These four internal cooling gas nozzles 103 spray cooling gas (air, nitrogen, argon, etc.) from the central part of each internal shape defining member 102a1, 102a2, 102a3 toward the casting M3 to cool the casting M3 from the inside. ing. At the same time, the internal cooling gas nozzle 103 supports the internal shape defining members 102a1, 102a2, and 102a3.

  The two support rods 104 support each of the external shape defining members 102b divided into two. The internal cooling gas nozzle 103 and the support rod 104 can maintain the positional relationship between the internal shape defining members 102a1, 102a2, 102a3 and the external shape defining member 102b. Further, the dividing operation or the combining operation of the shape defining member 102 can be performed.

  Two actuators 105 are connected to two internal cooling gas nozzles 103 and one support rod 104, respectively. The two actuators 105 can move the internal cooling gas nozzle 103 and the support rod 104 in the vertical direction (vertical direction) and the horizontal direction in synchronization. For this reason, the inner shape determining members 102a1, 102a2, 102a3 and the outer shape determining member 102b can be moved downward as the molten metal surface decreases due to the progress of casting. Further, the inner shape defining members 102a1, 102a2, 102a3 and the outer shape defining member 102b can be moved in the horizontal direction. Therefore, the shape of the casting M3 in the longitudinal direction can be freely changed, and the shape defining member 102 can be divided or joined.

  The external cooling gas nozzle (external cooling part) 106 is for blowing and cooling cooling gas (air, nitrogen, argon, etc.) on the casting M3. While the casting M3 is pulled up by a pulling machine (not shown) connected to the starter ST and the casting M3 is cooled by the cooling gas, the retained molten metal M2 near the solidification interface is sequentially solidified to form the casting M3. .

  Next, the details of the shape defining member 102 will be described with reference to FIGS. 2A and 2B. FIG. 2A is a plan view of the shape defining member 102 (when coupled). FIG. 2B is a plan view of the shape defining member 102 (when divided). As shown in FIGS. 2A and 2B, the shape defining member 102 includes internal shape defining members 102a1, 102a2, 102a3 and an external shape defining member 102b. Here, the cross-sectional views of the internal shape determining members 102a1, 102a2, 102a3 and the external shape determining member 102b in FIG. 1 correspond to the II cross-sectional view in FIG. 2A. Note that the xyz coordinates in FIGS. 2A and 2B coincide with those in FIG.

  As shown in FIG. 2A, the external shape defining member 102b has, for example, a substantially rectangular planar shape, and has a substantially rectangular opening at the center. As shown in FIG. 2B, the external shape defining member 102b can be divided in the x-axis direction along a symmetry axis parallel to the y-axis. 2A and 2B, the four corners of the external shape defining member 102b are chamfered. In addition, protrusions that protrude in the x-axis direction are provided at the four corners of the opening.

  As shown in FIG. 2A, each of the three internal shape defining members 102a1, 102a2, 102a3 has a substantially rectangular planar shape, and is arranged in the x-axis direction inside the opening of the external shape defining member 102b. . As shown in FIG. 2B, the internal shape defining member 102a2 located at the center of the shape defining member 102 can be divided in the x-axis direction along the symmetry axis parallel to the y-axis. The gaps between the internal shape defining members 102a1, 102a2, 102a3 and the external shape defining member 102b serve as a molten metal passage portion 102c (hatched portion) through which the molten metal passes.

  As shown in FIGS. 2A and 2B, the shape defining member 102 can be divided in the x-axis direction along a symmetry axis (partition line) parallel to the y-axis. That is, the shape defining member 102 can be switched between the combined state and the divided state. Therefore, the casting M3 can be branched by switching the shape defining member 102 from the coupled state to the divided state during casting. Further, the casting M3 that is branched can be integrated by switching the shape defining member 102 from the divided state to the coupled state during casting. That is, by using the shape defining member 102 according to the present embodiment, the casting M3 having a branch structure can be manufactured. Details of the casting M3 having such a branched structure will be described later.

  Next, with reference to FIG. 3A and 3B, the molten metal cutter for forming a branch structure in the casting M3 in cooperation with the shape defining member 102 will be described. FIG. 3A is a plan view showing a positional relationship between the shape defining member 102 and the molten metal cutters C1 and C2 (when the shape defining member 102 is coupled). FIG. 3B is a plan view showing the positional relationship between the shape defining member 102 and the molten metal cutters C1 and C2 (when the shape defining member 102 is divided). Note that the xyz coordinates in FIGS. 3A and 3B coincide with those in FIG.

  As shown in FIGS. 3A and 3B, the base portions of the two melt cutters C1 and C2 extending in the Y-axis direction are fixed to one ends of the arms A1 and A2 extending in the X-axis direction, respectively. The other ends of the arms A1 and A2 are slidably mounted on guides G extending in the Y-axis direction. With such a configuration, the molten metal cutters C1 and C2 can slide in the Y-axis direction.

  Here, the guide G can follow the shape defining member 102 and move on the XY plane and in the Z-axis direction. That is, the molten metal cutters C1 and C2 can follow the shape defining member 102 and move on the XY plane and in the Z-axis direction. The molten metal cutters C1 and C2 are disposed above the shape defining member 102 and below the solidification interface in the Z-axis direction. However, in order to improve the dimensional accuracy of the casting M3, it is preferable to provide the melt cutters C1 and C2 as close to the shape defining member 102 as possible.

  As shown in FIG. 3A, when the shape defining member 102 is coupled, the melt cutters C1 and C2 pass through the retained molten metal M2 pulled up from the shape defining member 102 on the axis of symmetry parallel to the Y axis of the shape defining member 102. Are opposed to each other. That is, the molten metal cutters C1 and C2 are not inserted into the retained molten metal M2.

  On the other hand, as shown in FIG. 3B, when the shape defining member 102 is divided, the molten metal cutters C1 and C2 move in the Y-axis direction so as to approach each other. Thereby, the division of the retained molten metal M2 by the division of the shape defining member 102 is promoted. If the shape defining member 102 is only divided, the retained molten metal M2 may not be divided as desired due to the surface tension of the retained molten metal M2. Therefore, the retained molten metal M2 can be reliably divided by inserting the melt cutters C1 and C2 into the retained molten metal M2 at the same time as the shape defining member 102 is divided. Thereby, the dimensional accuracy in the branch structure of the casting M3 can be improved.

Next, the casting M3 according to the first embodiment will be described with reference to FIGS.
FIG. 4 is a perspective view of the casting M3 according to the first embodiment. 5 is a cross-sectional perspective view taken along the line VV in FIG. The casting M3 according to Embodiment 1 can be used, for example, as a bumper (so-called front bumper) provided in front of the automobile, but the application is not particularly limited. Note that the xyz coordinates in FIGS. 4 and 5 coincide with those in FIG. Moreover, the casting M3 shown by FIG. 4, 5 is an example to the last, and will not be specifically limited if it is a casting which has a branched structure.

  As shown in FIG. 4, the casting M <b> 3 according to Embodiment 1 includes integral parts 201 and 203 and a branch part (branch structure) 202. The branch part 202 is provided with an opening 204 extending in the Y-axis direction. The opening 204 is used as a vent of a front bumper, for example. As shown in FIG. 4, the integral parts 201 and 203 have a structure in which three rectangular pipes P1 to P3 arranged in the X-axis direction are integrated. The integrated portions 201 and 203 are formed in a state where the shape defining member 102 shown in FIGS. 2A and 3A is coupled.

  In the branch portion 202, the central square pipe P2 is divided in the longitudinal (Z-axis) direction, and the square pipes P1 and P2 are curved so as to be separated from each other (on the opposite side in the X-axis direction). The branch portion 202 is formed in a state where the shape defining member 102 shown in FIGS. 2B and 3B is divided.

More specifically, when the shape defining member 102 is divided from the joined state during casting, the integrated portion 201 is switched to the formation of the branch portion 202.
Here, the division width of the shape defining member 102 is increased, and the width of the opening 204 in the branch portion 202 is also increased. Therefore, the interval between the square pipes P1, P3 is also increased.
Thereafter, while the divided width of the shape defining member 102 is kept constant, the width of the opening 204 in the branch portion 202 is also constant, and the square pipes P1 and P3 are parallel.
Thereafter, the division width of the shape defining member 102 is reduced, and the width of the opening 204 in the branch portion 202 is also reduced. Therefore, the interval between the square pipes P1 and P3 is also reduced.
When the shape defining member 102 is re-coupled during casting, the branch portion 202 is switched to the formation of the integrated portion 203.

Next, the free casting method according to Embodiment 1 will be described with reference to FIG.
First, the starter ST is lowered, and the tip of the starter ST is passed through the molten metal passage portion 102c between the internal shape determining members 102a1, 102a2, 102a3 and the external shape determining member 102b in a state in which the shape determining member 102 is coupled. Soak in. It is preferable to use a starter ST that has the same cross-sectional shape as the integral part 201 of the casting M3 and extends linearly in the longitudinal direction.

  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 retained molten metal M2 pulled up from the molten metal surface following the starter ST is formed by the surface film or surface tension. As shown in FIG. 1, the retained molten metal M2 is formed in the molten metal passage portion 102c between the inner shape defining members 102a1, 102a2, 102a3 and the outer shape defining member 102b. That is, the shape is imparted to the retained molten metal M2 by the inner shape defining members 102a1, 102a2, 102a3 and the outer shape defining member 102b.

  Next, since the starter ST is cooled by the cooling gas blown from the internal cooling gas nozzle 103 and the external cooling gas nozzle 106, the retained molten metal M2 is solidified in order from the upper side to the lower side, and the casting M3 grows. Go. In this way, the casting M3 can be continuously cast.

  As described above, in the free casting method according to the first embodiment, first, the integrated portion 201 (see FIG. 4) is formed in a state where the shape defining member 102 is coupled (see FIGS. 2A and 3A). Next, the branch portion 202 (see FIG. 4) is formed in a state where the shape defining member 102 is divided (see FIGS. 2B and 3B). Finally, the shape defining member 102 is recombined (see FIGS. 2A and 3A) to form the integrated portion 203 (see FIG. 4).

  The shape defining member 102 can also be moved in the horizontal direction while maintaining the relative positional relationship between the internal shape defining members 102a1, 102a2, 102a3 and the external shape defining member 102b. Thereby, besides a branched structure, various bending parts and curved parts can be given to casting M3.

  Instead of moving the internal shape defining members 102a1, 102a2, 102a3 and the external shape defining member 102b in the horizontal direction, the starter ST fixed to the pulling machine may be moved in the horizontal direction. Alternatively, the internal shape defining members 102a1, 102a2, 102a3, the external shape defining member 102b, and the starter ST may be moved in opposite directions within the horizontal plane.

  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. In particular, the casting M3 may have a solid structure instead of a hollow (pipe) structure.

101 Molten metal holding furnace 102 Shape defining member 102a1, 102a2, 102a3 Internal shape defining member 102b External shape defining member 102c Molten metal passage portion 103 Internal cooling gas nozzle 104 Support rod 105 Actuator 106 External cooling gas nozzle 201, 203 Integrated portion 202 Branching portion 204 Opening portion A1, A2 Arms C1, C2 Molten cutter G Guide M1 Molten metal M2 Retained molten metal M3 Cast P1-P3 Square pipe ST Starter

Claims (10)

A holding furnace for holding molten metal;
A shape defining member that is installed in the vicinity of the molten metal surface of the molten metal held in the holding furnace and that defines a cross-sectional shape of a casting to be cast by passing the molten metal;
The said shape prescription | regulation member is a pulling-up-type continuous casting apparatus which can switch a joining state and a division | segmentation state. When the shape defining member is in a divided state, the shape defining member further comprises a molten cutter inserted into the molten metal that has passed through the shape defining member.
The up-drawing continuous casting apparatus according to claim 1. The pair of molten metal cutters are arranged to face each other through the molten metal that has passed through the shape determining member on a dividing line where the shape determining member is divided.
The pulling-up-type continuous casting apparatus according to claim 2. The shape defining member includes an internal shape defining member and an external shape defining member, and a casting to be cast has a hollow structure.
The pulling-up-type continuous casting apparatus according to any one of claims 1 to 3. A cooling unit for cooling and solidifying the molten metal that has passed through the shape determining member;
The pulling-up-type continuous casting apparatus according to any one of claims 1 to 4. A step of pulling the molten metal held in the holding furnace through a shape defining member that defines the cross-sectional shape of the casting to be cast; and
Cooling and solidifying the molten metal that has been pulled up through the shape determining member,
A pulling-up-type continuous casting method in which the shape defining member is switched from a coupled state to a divided state during casting. During the casting, the shape defining member is switched from the divided state to the coupled state.
The pulling-up-type continuous casting method according to claim 6. When the shape defining member is in a divided state, a molten cutter is inserted into the molten metal that has passed through the shape defining member.
The pulling-up-type continuous casting method according to claim 6 or 7. A pair of the molten metal cutters are arranged to face each other through the molten metal that has passed through the shape determining member on a dividing line where the shape determining member is divided.
The pulling-up-type continuous casting method according to claim 8. The shape defining member is composed of an internal shape defining member and an external shape defining member, and casts a casting having a hollow structure.
The pulling-up-type continuous casting method according to any one of claims 6 to 9.

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