JP6616343B2 - Pull-up continuous casting equipment - Google Patents

Description

  The present invention relates to multiple piping.

  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. Therefore, it is possible to continuously cast a casting having a desired cross-sectional shape by deriving and cooling the molten metal through a shape determining member installed in the vicinity of the molten metal surface.

  In Patent Document 1, a hollow casting (that is, a pipe) is cast by using a shape defining member having an annular opening (a molten metal passage). Here, in patent document 1, it passes through the inside of the molten metal hold | maintained at the molten metal holding furnace from the exterior of a molten metal holding furnace, and is a cooling piping extended to the inner side of the molten metal derived | led-out from the molten metal surface of the molten metal holding furnace. By injecting a cooling medium from the tip of the hollow casting, the hollow casting being cast is cooled from the inside. This cooling pipe is a multiple pipe made up of a cooling gas nozzle for flowing a cooling medium and a protective pipe covering the cooling gas nozzle.

JP 2014-144484 A

The inventor has found the following problems.
In recent years, it has become possible to laminate and cool a cooling pipe having a multi-pipe structure disclosed in Patent Document 1 using a three-dimensional printing machine such as a 3D printer. Here, when a multi-layered pipe is layered using a three-dimensional printing machine, a bridge is usually provided between the inner pipe and the outer pipe in order to support the inner pipe.

  However, when a bridge is provided between the inner pipe and the outer pipe, there is a problem that it is difficult to remove the raw material powder remaining in the multiple pipe after the layered modeling. In order to avoid such a problem, when the outer diameter of the multiple pipe is enlarged, the multiple pipe provided in the molten metal holding furnace prevents the molten metal from being led out.

  This invention is made | formed in view of the above, Comprising: It aims at providing the multiple piping which can remove the raw material powder after layered modeling easily without enlarging an outer diameter.

  The multiple piping which concerns on 1 aspect of this invention is equipped with an inner side piping and the outer side piping provided so that the said inner side piping might be enclosed, The said outer side piping covers the outer peripheral surface of the said inner side piping in a cross sectional view And a part of the outward pipe formed from the outer peripheral surface of the inner pipe to the inner peripheral surface of the outer pipe, and so as to cover the outer peripheral surface of the outgoing pipe in a cross-sectional view. And a return pipe. Thereby, since it is not necessary to carry out additive manufacturing using a dedicated bridge, it is possible to easily remove the raw material powder after additive manufacturing without increasing the outer diameter of the pipe.

  According to the present invention, it is possible to provide a multiple pipe that can easily remove the raw material powder after layered modeling without enlarging the outer diameter.

It is sectional drawing which shows typically the free casting apparatus to which the multiple piping which concerns on Embodiment 1 is applied. It is a top view of the shape prescription | regulation member shown in FIG. It is sectional drawing which expands and shows typically the cooling part shown in FIG. It is the figure which looked at the multiple piping of the cooling unit shown in FIG. It is a perspective view for demonstrating the layered modeling process of the multiple piping of the cooling unit shown in FIG. It is the figure which looked at the 1st modification of the multiple piping of the cooling unit shown in FIG. It is the figure which looked at the 2nd modification of the multiple piping of the cooling unit shown in FIG. It is the figure which looked at the 3rd modification of the multiple piping of the cooling unit 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) to which the multiple piping according to Embodiment 1 is applied will be described. 1 is a cross-sectional view schematically showing a free casting apparatus to which multiple piping according to Embodiment 1 is applied.

  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, and a lifting machine. 116 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, the molten metal holding furnace 101 is not replenished with the molten metal M1 during casting, and therefore the surface of the molten metal M1 (that is, the molten metal surface) decreases with the progress of casting. On the other hand, the molten metal holding furnace 101 may be replenished with molten metal M1 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 outer shape defining member 103 and the inner 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 M1 passes. Note that the xyz coordinates in FIG. 2 coincide with those in FIG.

  2 also shows the tip 113 of the cooling gas supply pipe 112. The distal end portion 113 is disposed at the central portion of the internal shape defining member 104. The distal end portion 113 is provided with a plurality of injection ports 113a that open radially from the center of the internal shape defining member 104 in plan view.

  The pulling machine 116 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 by 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 solidifying 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. As a result, the outer shape determining member 103 and the inner shape determining member 104 (that is, the shape determining member 102) can be moved downward as the molten metal surface decreases due to the progress of casting. The actuator 108 can move the shape defining member 102 in the horizontal direction (x-axis direction and y-axis direction) via the support rods 106 and 107. Thereby, the shape of the casting M3 in the longitudinal direction can be freely deformed.

  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 pulling machine 116 and the shape defining member 102.

  More specifically, the cooling unit 109 includes a part that cools the casting M3 being cast from the outside and a part that cools the casting M3 from the inside, and has a cooling gas supply pipe 110 as a part that cools the casting M3 from the outside. As a part for cooling the casting M3 from the inside, a first cooling gas supply pipe (inner pipe) 112, a second cooling gas supply pipe (outward pipe of the outer pipe) 114, a second cooling gas discharge pipe (outer pipe) ) And a heat insulating layer 120.

FIG. 3 is a cross-sectional view schematically showing the cooling unit 109 in an enlarged manner.
First, in the part that cools the casting M3 from the outside, a plurality of tip portions 111 of the cooling gas supply pipe 110 are provided outside the casting M3 so as to surround the outer peripheral surface of the casting M3. The cooling gas supply pipe 110 injects the cooling gas A3 from the injection ports 111a of the plurality of tip portions 111 toward the outer peripheral surface of the hollow casting M3 being cast. Thereby, the outer peripheral surface of the retained molten metal M2 continuous with the casting M3 is indirectly cooled.

  Subsequently, in the cooling unit 109 that cools the casting M3 from the inside, the cooling gas supply pipe (inner piping) 112 is provided inside the molten metal M1 held in the molten metal holding furnace 101 from the outside of the molten metal holding furnace 101. It passes through and extends to the inner region of the hollow holding molten metal M2. That is, the distal end portion 113 of the cooling gas supply pipe 112 is provided so as to protrude from the molten metal surface to the inner region of the hollow retained molten metal M2. The cooling gas supply pipe 112 injects the cooling gas A <b> 1 from a plurality of injection ports 113 a provided at the distal end portion 113 toward the inner peripheral surface of the hollow casting M <b> 3 being cast. Thereby, the inner peripheral surface of the retained molten metal M2 continuous with the casting M3 is indirectly cooled.

  The cooling gas supply pipe (outward pipe of the outer pipe) 114 is provided so as to cover the outer peripheral surface of the cooling gas supply pipe 112. The cooling gas A2 flows through the cooling gas supply pipe 114. By adjusting the flow rate or temperature of the cooling gas A2, the temperature of the cooling gas A1 is adjusted. The discharge pipe (outward pipe return pipe) 115 is provided so as to continue to the cooling gas supply pipe 114 and cover the outer peripheral surface of the cooling gas supply pipe 114, and discharges the cooling gas A2 from the discharge port 115a to the outside of the apparatus. To do. Other refrigerants such as cooling water may be used instead of the cooling gas A2.

  That is, in the cooling unit 109, multiple piping is configured by the cooling gas supply pipes 112, 114, and 115. Therefore, the temperature of the cooling gas A1 flowing through the cooling gas supply pipe 112 located at the center of the multiple pipe is not easily affected by the hot molten metal M1. Moreover, in this example, the heat insulation layer 120 is provided so that the outer peripheral surface of this multiple piping may be covered. Therefore, the temperature of the cooling gas A1 is further less affected by the hot molten metal M1.

  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 pulling machine 116 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 pulling machine 116 can raise the position of the solidification interface SIF, and decreasing the pulling speed can lower the position of the solidification interface SIF.

  Instead of moving the shape defining member 102 in the horizontal direction, the pulling machine 116 may be moved in the horizontal direction. By pulling up the pulling machine 116 while moving in the horizontal direction, the retained molten metal M2 can be led out in an oblique direction. Therefore, the shape of the casting M3 in the longitudinal direction can be freely changed.

  Next, the free casting method according to the first embodiment will be described with reference to FIGS. 1 to 3. First, the starter ST is lowered by the pulling machine 116, 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.

  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.

  Next, the starter ST or the casting M3 formed by solidifying the retained molten metal M2 is cooled by the cooling gas blown out from the cooling unit 109. Thereby, the holding molten metal M2 continuous with the starter ST or the casting M3 is indirectly cooled and solidified in order from the upper side to the lower side, and the casting M3 grows. In this way, the casting M3 can be continuously cast.

(Cross-section structure of multiple piping)
By the way, in recent years, it has become possible to laminate and model the multiple piping of the cooling unit 109 using a three-dimensional printing machine such as a 3D printer. Here, when layered modeling of multiple pipes using a three-dimensional printing machine, since layered modeling is not possible in a state where the inner pipe (cooling gas supply pipe 112) is floating in the cross section, A bridge is provided between the outer pipe. However, when a bridge is provided between the inner pipe and the outer pipe, there is a problem that it is difficult to remove the raw material powder remaining in the multiple pipe after the layered modeling. In order to avoid such a problem, when the outer diameter of the multiple pipe is enlarged, the multiple pipe provided in the molten metal holding furnace prevents the molten metal from being led out.

  Therefore, in the multiple piping according to the present embodiment, by adopting a structure that does not use a bridge, it is possible to easily remove the raw material powder after layered modeling without increasing the outer diameter. Hereinafter, a specific example will be described.

FIG. 4 is a cross-sectional view of the multiple piping of the cooling unit 109.
As shown in FIG. 4, in the multiple pipe, a cooling gas supply pipe (inner pipe) 112 is provided at the center portion in cross section, and an outer pipe 119 is provided so as to surround it. The outer pipe 119 includes a cooling gas supply pipe (outward pipe of the outer pipe) 114 and a discharge pipe (return pipe of the outer pipe) 115.

  The cooling gas supply pipe (outward pipe of the outer pipe) 114 is divided into four cooling gas supply pipes 114_1 to 114_4 having a substantially triangular shape in cross section.

  In the cooling gas supply pipes 114_1 to 114_4, one side of each substantially triangular shape covers all or most of the outer peripheral surface of the cooling gas supply pipe (inner pipe) 112. Thereby, the temperature of the cooling gas A1 flowing through the cooling gas supply pipe 112 can be efficiently adjusted using the cooling gas A2 flowing through the cooling gas supply pipe 114.

  Further, in the cooling gas supply pipes 114 </ b> _ <b> 1 to 114 </ b> _ 4, the remaining two substantially triangular sides are formed from the outer peripheral surface of the cooling gas supply pipe (inner pipe) 112 to the inner peripheral face of the outer pipe 119. That is, a part of the cooling gas supply pipe 114 has a function equivalent to that of the bridge, and is formed from the cooling gas supply pipe (inner pipe) 112 to the inner peripheral surface of the outer pipe 119. Thereby, this multiple piping can be layered without a dedicated bridge.

  The discharge pipe 115 is divided into four substantially triangular discharge pipes 115_1 to 115_4 in cross-sectional view. The exhaust pipes 115_1 to 115_4 are provided in the gaps between the cooling gas supply pipes 114_1 to 114_4, respectively.

  Here, most of the inner peripheral surface of the outer pipe 119 is covered with the discharge pipes 115_1 to 115_4, and the cooling gas supply pipes 114_1 to 114_4 have their substantially triangular apexes at the inner circumference of the outer pipe 119. It is a grade which is made to contact the surface. Therefore, the cooling gas A2 flowing through the cooling gas supply pipes 114_1 to 114_4 is not easily affected by the heat from the molten metal M1 outside the outer pipe 119.

  The heat insulating layer 120 is provided so as to surround the outer peripheral surface of the outer pipe 119 in a cross-sectional view. Although the heat insulation layer 120 is not essential, the heat conduction from the molten metal M1 to the inside of the multiple pipe can be further suppressed.

  The heat insulation layer 120 has, for example, a space region (air layer) in which air is enclosed. Here, the raw material powder may remain in the space region. Thereby, heat conduction by radiation such as infrared rays can be suppressed. When a space region is provided in the heat insulating layer 120, a bridge is provided in the space region between the outer pipe 119 and the outer peripheral wall of the heat insulating layer 120.

  FIG. 5 is a perspective view showing the layered manufacturing process of the multiple piping of the cooling unit 109. As illustrated in FIG. 5, the multiple piping of the cooling unit 109 is layered and formed in the order of steps A, B, C, and D using a three-dimensional printing machine such as a 3D printer. As can be seen from FIG. 5, the multiple piping according to the present embodiment can be layered without a dedicated bridge.

  As described above, in the multiple piping according to the present embodiment, the cooling gas supply pipe (inner pipe) 112 is assumed that a part of the cooling gas supply pipe (outward pipe of the outer pipe) 114 has the same function as the bridge. To the inner peripheral surface of the outer pipe 119. As a result, the multiple piping according to the present embodiment does not need to be layered using a dedicated bridge, so that the raw material powder after layered modeling can be easily removed without increasing the outer diameter.

(First variation of multiple piping)
FIG. 6 is a cross-sectional view of a first modification of the multiple piping of the cooling unit 109.
The multiple piping shown in FIG. 6 further includes a powder residual portion 121 at each corner of the cooling gas supply pipes 114_1 to 114_4 in a cross-sectional view as compared to the multiple piping shown in FIG. The other structure of the multiple pipe shown in FIG. 6 is the same as that of the multiple pipe shown in FIG.

  The powder residual part 121 plays the role of a heat insulating material by, for example, leaving the raw material powder after layered modeling. Thereby, the powder residual part 121 can suppress the heat conduction from the molten metal M1 to the inside of the multiple pipe.

(Second modified example of multiple piping)
FIG. 7 is a cross-sectional view of a second modification of the multiple piping of the cooling unit 109.
The multiple piping shown in FIG. 7 further includes a metal foil 122 in the space region of the heat insulating layer 120 in a sectional view as compared to the multiple piping shown in FIG. The other structure of the multiple pipe shown in FIG. 7 is the same as that of the multiple pipe shown in FIG.

  By providing the metal foil 122 in the space region of the heat insulating layer 120, heat conduction due to radiation can be further suppressed. The metal foil 122 may also be used as a bridge that connects the outer pipe 119 and the heat insulating layer 120.

(Third modification of multiple piping)
FIG. 8 is a cross-sectional view of a third modification of the multiple piping of the cooling unit 109.
In the multiple piping shown in FIG. 8, the cooling gas supply pipe 114 is divided into three cooling gas supply pipes 114_1 to 114_3 instead of being divided into four compared to the multiple pipe shown in FIG. Instead of being divided into four, it is divided into three cooling gas supply pipes 115_1 to 115_3. The other structure of the multiple pipe shown in FIG. 8 is the same as that of the multiple pipe shown in FIG.

  The multiple piping shown in FIG. 8 can achieve the same effect as the multiple piping shown in FIG. The cooling gas supply pipe 114 and the exhaust pipe 115 are not limited to being divided into three or four, and can be divided into any number.

  Moreover, the above-mentioned powder residual part 121 and metal foil 122 may be provided with respect to the multiple piping shown in FIG.

  As described above, in the multiple piping according to the above-described embodiment, a part of the cooling gas supply pipe (outward pipe of the outer pipe) 114 has a function equivalent to that of the bridge, and the cooling gas supply pipe (inner pipe) 112 to the inner peripheral surface of the outer pipe 119. As a result, the multiple piping according to the above embodiment does not need to be layered using a dedicated bridge, and thus the raw material powder after layered modeling can be easily removed without increasing the outer diameter.

  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. For example, although the case where the heat insulation layer 120 was provided in multiple piping was demonstrated in the said embodiment, it is not restricted to this, The heat insulation layer 120 does not need to be provided if it is unnecessary.

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 pipe 111 Tip part 111a Injection port 112 Cooling gas supply pipe ( Inner piping)
113 tip portion 113a injection port 114 cooling gas supply pipe (outward pipe of outer pipe)
114_1 to 114_4 Cooling gas supply pipe 115 Discharge pipe (outward return pipe)
115_1 to 115_4 Discharge pipe 115a Discharge port 116 Pull-up machine 119 Outer piping 120 Thermal insulation layer 121 Powder residue 122 Metal foil A1 to A3 Cooling gas M1 Molten metal M2 Retained molten metal M3 Casting SIF Solidification interface ST Starter

Claims (4)

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 pulling-up-type continuous casting apparatus comprising: a cooling unit that cools the inside of the molten molten metal led out from the molten metal surface,
The cooling part is
The first refrigerant passes through the inside of the molten metal held in the holding furnace and is ejected from the injection port at the tip protruding from the molten metal surface toward the inner region of the hollow molten metal led out from the molten metal surface. Inner piping to inject ,
An outer pipe that is provided so as to surround the inner pipe and through which a second refrigerant for adjusting the temperature of the first refrigerant flowing through the inner pipe flows ;
With
The outer pipe is
A cross-sectional view, provided to cover the outer peripheral surface of the inner pipe, and a part of the forward pipe formed from the outer peripheral surface of the inner pipe to the inner peripheral surface of the outer pipe;
In cross section, a return pipe provided to cover the outer peripheral surface of the forward pipe;
An up-drawing continuous casting apparatus.   In each corner of the forward pipe and the backward pipe, the raw material powder of the cooling unit is provided,
  The up-drawing continuous casting apparatus according to claim 1.   The cooling part is
  A heat insulating layer provided so as to surround the outer peripheral surface of the outer pipe;
  The up-drawing continuous casting apparatus according to claim 1 or 2.   The thermal insulation layer is
  Having a metal foil formed so as to surround the outer peripheral surface of the outer pipe;
  The up-drawing continuous casting apparatus according to claim 3.

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