JP2015100835A - Upward continuous casting apparatus and upward continuous casting method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an upward continuous casting apparatus and an upward continuous casting method capable of improving mold productivity.SOLUTION: An upward continuous casting apparatus according to one aspect of the present invention includes: a molten-metal holding furnace 101 holding molten metal M1; a shape defining member 102 installed on a molten metal surface of the molten metal M1, and defining a sectional shape of a mold M3 to be cast by passing the held molten metal M1 withdrawn from the molten metal surface through the shape defining member 102; a light source 108 radiating light; an optical sensor 109 arranged to be opposite to the light source 108 across the mold M3, and detecting the light; and a monitor 110 determining that a hole is formed in the mold M3 if an intensity of the light detected by the optical sensor 109 is equal to or higher than a reference intensity.

Description

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

  Patent Document 1 proposes a free casting method as an innovative pull-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. Therefore, castings with various shapes in the longitudinal direction can be obtained by pulling up the starter while moving the starter (or shape defining member) in the horizontal direction. 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.
In the free casting method described in Patent Document 1, an unintended hole may be formed in the casting while the casting is in progress, depending on the starter pulling speed, the cooling condition of the casting, and the like. However, in the free casting method described in Patent Document 1, since there is no means for automatically finding a hole opened in the casting, it is necessary to visually confirm whether or not the hole is opened in the casting. Therefore, in the free casting method described in Patent Document 1, casting time and material may be wasted due to oversight of the hole, and as a result, there is a problem that the productivity of the casting is lowered.

  This invention is made | formed in view of the above, Comprising: It aims at providing the pull-up-type continuous casting apparatus and pull-up-type continuous casting method which can improve the productivity of a casting.

  The up-drawing continuous casting apparatus according to an aspect of the present invention is cast by a holding furnace for holding a molten metal and the molten metal that is installed on the molten metal surface and that is led out from the molten metal surface. A pull-up type continuous casting apparatus comprising a shape defining member that defines a cross-sectional shape of a casting, and a signal source that emits a signal that is capable of propagating in space while being suppressed by the casting, and It is determined that a hole is formed in the casting only when the signal is detected by the sensor that is disposed opposite to the signal source across the casting and the signal detected by the sensor is equal to or higher than a reference strength. Determination means. As a result, it is possible to automatically determine whether or not there is a hole in the casting while the casting is in progress, so that the productivity of the casting can be improved.

  The pulling-up-type continuous casting method according to one aspect of the present invention is a method of casting a casting by deriving the molten metal from a molten metal surface held in a holding furnace and passing the shape determining member, While the casting is in progress, the step of detecting a signal that can be propagated through the space while the propagation is suppressed by the casting through the casting, and only when the intensity of the detected signal is equal to or higher than a reference strength. And a step of determining that the casting has a hole. As a result, it is possible to automatically determine whether or not there is a hole in the casting while the casting is in progress, so that the productivity of the casting can be improved.

  According to the present invention, it is possible to provide a pulling-up-type continuous casting apparatus and a pull-up-type continuous casting method that can improve the productivity of castings.

1 is a cross-sectional view schematically showing a free casting apparatus according to Embodiment 1. FIG. 3 is a plan view of a shape defining member 102 according to Embodiment 1. FIG. 1 is a perspective view schematically showing a part of a free casting apparatus according to Embodiment 1. FIG. 2 is a plan view schematically showing a part of the free casting apparatus according to Embodiment 1. FIG. 6 is a timing chart showing a monitoring result (the intensity of light detected by an optical sensor 109) by a monitor 110 provided in the free casting apparatus according to Embodiment 1. It is sectional drawing which shows typically the modification of the free casting apparatus which concerns on Embodiment 1. FIG. It is a perspective view which shows typically a part of modification of the free casting apparatus which concerns on Embodiment 1. FIG. It is sectional drawing which shows typically the free casting apparatus which concerns on Embodiment 2. FIG. 6 is a plan view of a shape defining member 102 according to Embodiment 2. FIG. FIG. 6 is a plan view schematically showing a part of a free casting apparatus according to a second embodiment. 10 is a timing chart showing generation of light by light sources 108a and 108b provided in the free casting apparatus according to Embodiment 2 and intensity of light detected by optical sensors 109a and 109b. It is a top view which shows typically a part of 1st modification of the free casting apparatus which concerns on Embodiment 2. FIG. It is a top view which shows typically a part of 2nd modification of the free casting apparatus which concerns on Embodiment 2. FIG. It is a top view which shows typically a part of 3rd modification of the free casting apparatus which concerns on Embodiment 2. FIG.

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

<Embodiment 1>
First, with reference to FIG. 1, the free casting apparatus (pull-up type continuous casting apparatus) according to Embodiment 1 will be described. 1 is a cross-sectional view schematically showing a free casting apparatus according to Embodiment 1. FIG. As shown in FIG. 1, a free casting apparatus according to Embodiment 1 includes a molten metal holding furnace (holding furnace) 101, an external shape defining member 102a, an internal shape defining member 102b, support rods 103 and 104, an actuator 105, and a cooling gas nozzle. (Cooling unit) 106, pulling machine 107, light source 108, optical sensor 109, and monitor (determination unit) 110 are provided.
In FIG. 1, the right-handed xyz coordinates are shown for 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 (for example, about 720 ° C.) having fluidity. In the example of FIG. 1, since the molten metal is not replenished to the molten metal holding furnace 101 during casting, the surface of the molten metal M1 (that is, the molten metal surface) decreases as the casting progresses. On the other hand, the molten metal may be replenished to the molten metal holding furnace 101 at any time during casting to keep the molten metal surface constant. Here, when the set temperature of the molten metal holding furnace 101 is raised, the position of the solidification interface SIF can be raised, and when the set temperature of the molten metal holding furnace 101 is lowered, the position of the solidified interface SIF can be lowered. As a matter of course, the molten metal M1 may be a metal other than aluminum or an alloy thereof.

  The external shape defining member 102a and the internal shape defining member 102b are made of, for example, ceramics or stainless steel, and are disposed on the molten metal M1. The external shape defining member 102a defines the external cross-sectional shape of the casting M3 to be cast, and the internal shape defining member 102b 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 other words, the casting M3 shown in FIG. 1 is a hollow casting having one through hole extending from the upper surface toward the lower surface.

  In the example of FIG. 1, the outer shape defining member 102a and the inner shape defining member 102b 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 102a and the inner shape defining member 102b may be installed such that their lower surfaces do not contact the hot water surface. Specifically, the outer shape defining member 102a and the inner shape defining member 102b 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 102a and the internal shape defining member 102b, since thermal deformation and melting damage are suppressed, durability is improved.

  FIG. 2 is a plan view of the outer shape defining member 102a and the inner shape defining member 102b. Here, the cross-sectional views of the external shape defining member 102a and the internal shape defining member 102b in FIG. 1 correspond to the II cross-sectional view in FIG. As shown in FIG. 2, the external shape defining member 102a has, for example, a rectangular planar shape, and has a rectangular opening at the center. The internal shape defining member 102b has a rectangular planar shape and is disposed at the center of the opening of the external shape defining member 102a. A gap between the outer shape defining member 102a and the inner shape defining member 102b becomes a molten metal passage portion 102c through which the molten metal passes. As described above, the shape defining member 102 is configured by the external shape defining member 102a, the internal shape defining member 102b, and the molten metal passage portion 102c. Note that the xyz coordinates in FIG. 2 coincide with those in FIG.

  The pulling machine 107 holds the starter (leading member) ST and immerses the starter ST in the molten metal M1 or pulls up the starter ST immersed in the molten metal M1.

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

  The starter ST is made of, for example, ceramics or stainless steel. Note that the surface of the starter ST may be covered with a protective film such as a salt crystal. Thereby, since the melt bond between the starter ST and the molten metal M1 is suppressed, the peelability between the starter ST and the casting M3 can be improved. As a result, the starter ST can be reused. Further, when the surface of the starter ST is covered with a protective film, the surface of the starter ST preferably has an uneven shape. Thereby, since it becomes easy to adhere (deposit) a protective film on the surface of the starter ST, the peelability between the starter ST and the casting M3 can be further improved. At the same time, it is possible to improve the coupling force in the pulling direction between the starter ST and the molten metal M1 when the molten metal is led out.

  The support rod 103 supports the external shape defining member 102a, and the support rod 104 supports the internal shape defining member 102b. Here, if the support rod 104 has a pipe structure, a cooling gas is allowed to flow through the support rod 104, and a blow hole is provided in the internal shape defining member 102b, the casting M3 can be cooled also from the inside.

  Both support rods 103 and 104 are connected to the actuator 105. The actuator 105 can move the external shape defining member 102 a and the internal shape defining member 102 b in the vertical direction (z-axis direction) via the support rods 103 and 104. Thereby, the shape determining member 102 can be moved downward as the molten metal surface is lowered due to the progress of casting.

  The cooling gas nozzle 106 is for blowing a cooling gas (air, nitrogen, argon, etc.) on the starter ST or the casting M3 to cool it. 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 gas nozzle 106 is also movable in the vertical direction (z-axis direction) and the horizontal direction (x-axis direction and y-axis direction). Therefore, for example, the cooling gas nozzle 106 can be moved downward in accordance with the downward movement of the shape defining member 102 as the molten metal surface decreases due to the progress of casting. Alternatively, the cooling gas nozzle 106 can be moved in the horizontal direction in accordance with the horizontal movement of the pulling machine 107.

  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 107 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 107 can raise the position of the solidification interface SIF, and slowing the pulling speed can lower the position of the solidification interface SIF. Further, the shape of the casting M3 in the longitudinal direction can be freely changed by pulling up the lifting machine 107 while moving it in the horizontal direction (x-axis direction or y-axis direction). Note that the shape of the casting M3 in the longitudinal direction may be freely changed by moving the shape determining member 102 in the horizontal direction instead of moving the pulling machine 107 in the horizontal direction.

  The light source 108 emits light. The optical sensor 109 detects light. Specifically, the optical sensor 109 detects light from the light source 108 through the casting M3.

  3 and 4 are a perspective view and a plan view schematically showing a part of the free casting apparatus according to the present embodiment. FIG. 3 shows only the shape defining member 102, the light source 108, the optical sensor 109, the monitor 110, the starter ST, and the casting M3. FIG. 4 shows only the light source 108, the optical sensor 109, and the casting M3. The xyz coordinates in FIGS. 3 and 4 are the same as those in FIG.

  As shown in FIGS. 3 and 4, in the present embodiment, four light sources 108 are arranged so as to surround the outer periphery of the casting M3. In other words, the four light sources 108 are arranged to emit light from the outside toward the four side walls of the rectangular tube-shaped casting M3. In the present embodiment, one optical sensor 109 is arranged in a cylinder of a rectangular tube-shaped casting M3. In other words, one optical sensor 109 is arranged to face the four light sources 108 with the casting M3 interposed therebetween.

  For example, when a hole is opened in the side wall of the casting M3, the light emitted from the outside of the casting M3 propagates through the hole and propagates to the inside. Therefore, the optical sensor 109 detects light having an intensity higher than the reference intensity. . On the other hand, when there is no hole in the side wall of the casting M3, the light does not propagate from the outside to the inside of the casting M3, so the optical sensor 109 does not detect light having a reference intensity or higher.

  A monitor (determination unit) 110 monitors the intensity of light detected by the optical sensor 109 during the progress of casting. Then, the monitor 110 determines whether or not there is a hole in the casting M3 based on the monitoring result.

  FIG. 5 is a timing chart showing a monitoring result by the monitor 110 (light intensity detected by the optical sensor 109). For example, when the intensity of the light detected by the optical sensor 109 is equal to or higher than the reference intensity (time t1 to t2 and time t3 to t4), the monitor 110 determines that the casting M3 has a hole, and the reference When it is less than the strength, it is determined that the casting M3 has no hole.

  The monitor 110 determines that the hole is large in the vertical direction (z-axis direction) when the intensity of the light detected by the optical sensor 109 is longer than the reference intensity, and the period when the intensity is higher than the reference intensity is short. In this case, it is determined that the hole is small in the vertical direction (z-axis direction). Furthermore, when the intensity of light detected by the optical sensor 109 is equal to or higher than the reference intensity, the monitor 110 determines that the hole is large in the lateral direction (x-axis direction and y-axis direction) when the intensity of the light is large. When the intensity of the light is small, it is determined that the hole is small in the lateral direction (x-axis direction and y-axis direction). That is, the monitor 110 can determine not only the presence or absence of a hole in the casting M3 but also the size of the hole in the casting M3.

  The monitor 110 and the optical sensor 109 are connected by wire. In the present embodiment, the optical sensor 109 is arranged so as to be suspended in the cylinder of the casting M3 by wire from the vicinity of the pulling machine 107. Thereby, it can prevent that a wire contact | connects the casting M3.

  The light source 108 and the optical sensor 109 are preferably provided as low as possible in the vicinity of the shape defining member 102. Thereby, it can be discovered at an early stage whether or not a hole is formed in the casting M3 while the casting is in progress.

Next, the free casting method according to the present embodiment will be described with reference to FIG.
First, the starter ST is lowered by the pulling machine 107 and the molten metal passage portion 102c between the external shape defining member 102a and the internal shape defining member 102b is passed, and the tip end (lower end) of the starter ST is made into the molten metal M1. Soak.

  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 M2 is formed in the molten metal passage portion 102c. That is, the shape defining member 102 imparts a shape to the retained molten metal M2.

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

  Here, when the optical sensor 109 disposed opposite to the light source 108 across the casting M3 has a hole in the side wall of the casting M3 being cast, light from the light source 108 that has passed through the hole exceeds the reference intensity. Detect as intense light. The monitor 110 monitors the intensity of light detected by the optical sensor 109, and determines that the hole is formed in the casting M3 when the intensity of the light is equal to or higher than the reference intensity. When it is determined that the hole is formed in the casting M3, for example, casting of the casting is stopped.

  As described above, the free casting apparatus according to the present embodiment is in progress of casting by detecting whether the light from the light source 108 is detected by the optical sensor 109 via the casting M3, thereby determining whether the casting M3 has a hole. Can be determined automatically. This eliminates the oversight of holes that can occur in the case of visual observation, so that casting time and materials are not wasted. In addition, by finding the hole while the casting is in progress, the casting can be stopped before the casting is completed, so that casting time and materials are not wasted. As a result, the free casting apparatus according to the present embodiment can improve casting productivity.

  Although the case where the light source 108 is provided outside the casting M3 and the optical sensor 109 is provided inside the casting M3 has been described as an example in the present embodiment, the present invention is not limited thereto. The light source 108 may be provided inside the casting M3, and the optical sensor 109 may be provided outside the casting M3.

  In the present embodiment, the case where the casting M3 is a hollow casting has been described as an example, but the present invention is not limited thereto. The casting M3 may be a solid casting whose cross section is circular or rectangular. In this case, by arranging the light source 108 and the optical sensor 109 to face each other across the solid casting, it is possible to determine whether or not the solid casting has a hole.

  Furthermore, in this embodiment, the case where the optical sensor 109 and the monitor 110 are connected by wire is described as an example, but the present invention is not limited to this. The optical sensor 109 and the monitor 110 may be configured to perform wireless communication. Hereinafter, a brief description will be given with reference to FIGS. 6 and 7.

  FIG. 6 is a cross-sectional view schematically showing a modified example of the free casting apparatus according to the present embodiment. FIG. 7 is a perspective view schematically showing a modification of a part of the free casting apparatus according to the present embodiment. FIG. 6 corresponds to FIG. 1, and FIG. 7 corresponds to FIG. Note that the xyz coordinates in FIGS. 6 and 7 are the same as those in FIG.

  As shown in FIGS. 6 and 7, the optical sensor 109 and the monitor 110 perform wireless communication. In the example of FIGS. 6 and 7, four light sources 108 and one optical sensor 109 are arranged on the upper surface of the shape defining member 102 via a heat insulating material. Other configurations and operations of the free casting apparatus shown in FIGS. 6 and 7 are the same as those of the free casting apparatus shown in FIGS. With such a configuration, since the wire does not come into contact with the casting M3, the degree of freedom in casting is increased.

<Embodiment 2>
FIG. 8 is a cross-sectional view schematically showing a free casting apparatus according to the second embodiment. The free casting apparatus shown in FIG. 8 differs from the free casting apparatus shown in FIG. The other configuration of the free casting apparatus shown in FIG. 8 is the same as that of the free casting apparatus shown in FIG.

  FIG. 9 is a plan view of the shape defining member 102 according to the present embodiment. Here, the cross-sectional view of the shape defining member 102 in FIG. 8 corresponds to the II-II cross-sectional view in FIG. 9. As shown in FIG. 9, the external shape defining member 102a has, for example, a rectangular planar shape, and has a rectangular opening at the center. The internal shape defining member 102b is composed of four members having a rectangular planar shape, and these four members are arranged at predetermined intervals in a matrix at the openings of the external shape defining member 102a. A gap between the outer shape defining member 102a and the inner shape defining member 102b becomes a molten metal passage portion 102c through which the molten metal passes. As described above, the shape defining member 102 is configured by the external shape defining member 102a, the internal shape defining member 102b, and the molten metal passage portion 102c. In addition, the xyz coordinate in FIG. 9 corresponds with FIG.

  The free casting apparatus according to the present embodiment casts a hollow casting M3 having a plurality of openings in a horizontal cross section (cross section) by performing casting using the shape determining member 102 shown in FIG. To do. That is, the free casting apparatus according to the present embodiment casts a hollow casting M3 having partition walls (ribs) inside by performing casting using the shape defining member 102 shown in FIG. In other words, the free casting apparatus according to the present embodiment performs a plurality of (four in this example) penetrations extending from the upper surface to the lower surface by performing casting using the shape defining member 102 shown in FIG. A hollow casting M3 having holes is cast.

  Next, the positional relationship between the light source 108 and the optical sensor 109 will be described with reference to FIG. FIG. 10 is a plan view schematically showing a part of the free casting apparatus according to the present embodiment. FIG. 10 shows only the light source 108, the optical sensor 109, and the casting M3. In addition, the xyz coordinate in FIG. 10 corresponds with FIG.

  As shown in FIG. 10, in this embodiment, two light sources 108 (hereinafter referred to as light sources 108a and 108b) and two optical sensors 109 (hereinafter referred to as optical sensors 109a and 109b) are provided. The light source 108a and the optical sensor 109a are arranged to face each other with a partition wall F1 therebetween. The light source 108a and the optical sensor 109b are disposed to face each other with a partition wall F2. The light source 108b and the optical sensor 109a are disposed to face each other with a partition wall F3 therebetween. The light source 108b and the optical sensor 109b are disposed to face each other with a partition wall F4 interposed therebetween.

  Thereby, it is possible to determine whether or not a hole is opened in the partition wall F1 of the casting M3 using the light source 108a and the optical sensor 109a. It is possible to determine whether or not there is a hole in the partition wall F2 of the casting M3 using the light source 108a and the optical sensor 109b. It is possible to determine whether or not there is a hole in the partition wall F3 of the casting M3 using the light source 108b and the optical sensor 109a. It is possible to determine whether or not there is a hole in the partition wall F4 of the casting M3 using the light source 108b and the optical sensor 109b.

  FIG. 11 is a timing chart showing the generation of light by the light sources 108a and 108b and the intensity of light detected by the optical sensors 109a and 109b. In the example of FIG. 11, the light source 108a emits light at times t0 to t1, times t4 to t5, and times t8 to t9. The light source 108b emits light at time t2 to t3, time t6 to t7, and time t10 to t11. The optical sensor 109a does not detect light having a reference intensity or higher during the period from time t0 to t12. On the other hand, the optical sensor 109b detects light having an intensity equal to or higher than the reference intensity during the period from time t2 to time t3. In this case, it is determined that there is a hole in the partition wall F4 of the casting M3 between the light source 108b that emits light during the period of time t1 to t3 and the optical sensor 109b that detects the light.

  As described above, the free casting apparatus according to the present embodiment can achieve the same effects as the free casting apparatus according to the first embodiment, and when casting a hollow casting M3 having a partition wall therein, a light source By arranging 108 and the optical sensor 109 facing each other inside the hollow casting M3 with a partition wall therebetween, it is possible to determine whether or not there is a hole in the partition wall of the casting M3 that cannot be visually confirmed from the outside.

  As shown in the plan views of FIGS. 12 to 14, regarding the arrangement of the light source 108 and the optical sensor 109, the cross-sectional shape and number of through-holes in the casting M <b> 3 (the shape and number of openings when viewed in plan) are used. There is no limit.

  Also in the present embodiment, as in the case of the first embodiment, the optical sensor 109 and the monitor 110 may be configured to perform wireless communication. Thereby, the wire does not come into contact with the casting M3, so that the degree of freedom in casting is increased.

  As described above, the free casting apparatus according to the first and second embodiments detects whether the casting M3 has a hole by detecting the light from the light source 108 with the optical sensor 109 via the casting M3. It can be automatically determined while the casting is in progress. This eliminates the oversight of holes that can occur in the case of visual observation, so that casting time and materials are not wasted. In addition, by finding the hole while the casting is in progress, the casting can be stopped before the casting is completed, so that casting time and materials are not wasted. As a result, the free casting apparatus according to the first and second embodiments can improve casting productivity. Furthermore, the free casting apparatus according to the second embodiment can also determine whether or not there is a hole in the partition wall of the casting M3 that cannot be visually confirmed from the outside.

  In the first and second embodiments, the case where the light source 108 and the optical sensor 109 are provided has been described as an example, but the present invention is not limited thereto. It is only necessary to provide a signal source that emits a signal that can be propagated through the space but is suppressed by the casting M3 (obstacle), and a sensor that can receive the signal. For example, instead of the light source 108 and the optical sensor 109, a radio wave source that emits radio waves and a sensor that receives radio waves may be provided, or a sound wave source that emits sound waves such as ultrasonic waves and a sensor that receives sound waves are provided. May be.

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

DESCRIPTION OF SYMBOLS 101 Molten metal holding furnace 102 Shape defining member 102a External shape defining member 102b Internal shape defining member 102c Melt passage part 103 Support rod 104 Support rod 105 Actuator 106 Cooling gas nozzle 107 Pull-up machine 108 Light source 109 Optical sensor 110 Monitor F1-F4 Partition wall M1 Molten metal M2 Holding molten metal M3 Casting SIF Solidification interface ST Starter

Claims (9)

A holding furnace for holding molten metal;
And a shape defining member that defines a cross-sectional shape of a casting to be cast by passing the molten metal led out of the molten metal and passing through the molten metal. And
A signal source that emits a signal that is capable of propagating in space while being suppressed by the casting;
A sensor that is disposed opposite the signal source across the casting and that detects the signal;
A pulling-up-type continuous casting apparatus comprising: a determination unit that determines that a hole is formed in the casting only when the intensity of the signal detected by the sensor is equal to or higher than a reference intensity.   The pulling-up-type continuous casting apparatus according to claim 1, wherein the signal is any one of light, radio waves, and sound waves. The casting is a hollow casting,
The signal source is disposed on one of the outside and the inside of the hollow casting,
The pulling-up-type continuous casting apparatus according to claim 1 or 2, wherein the sensor is arranged on the other of the outside and the inside of the hollow casting. The casting is a hollow casting having a partition wall inside,
The pulling-up-type continuous casting apparatus according to claim 1 or 2, wherein the signal source and the sensor are arranged to face each other with the partition wall inside the hollow casting. A method of casting a casting by deriving the molten metal from a molten metal surface held in a holding furnace and passing the shape determining member,
During the casting process,
Detecting through the casting a signal that is capable of propagating in space while being inhibited by the casting;
And a step of determining that the casting has a hole only when the detected intensity of the signal is equal to or higher than a reference intensity.   The pulling-up-type continuous casting method according to claim 5, wherein the signal is any one of light, radio waves, and sound waves.   The pulling of claim 5 or 6, wherein in the step of detecting the signal, the signal emitted from one of the outside and the inside of the casting that is a hollow casting is detected at the other of the outside and the inside of the casting. Upper continuous casting method.   The pulling-up type according to claim 5 or 6, wherein, in the step of detecting the signal, the signal emitted from the inside of the casting which is a hollow casting having a partition wall therein is detected through the partition wall. Continuous casting method.   The pulling-up-type continuous casting method according to any one of claims 5 to 8, further comprising a step of stopping casting of the casting when it is determined that a hole is formed in the casting.

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