JP2009279628A - Unidirectional solidification casting apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a unidirectional solidification casting apparatus in which a boundary between a heating region and a cooling region is clear, and a temperature difference in the radius direction is eliminated upon heating and upon cooling. <P>SOLUTION: The central part of an external heating means 9 with a cylindrical shape is concentrically provided with an inner cylinder 8, and a cylindrical space 10 is formed between the inner cylinder and the external heating means. The required number of molds 23 can be stored in the space, and the molds are arranged in the circumferential direction at a ring-like mold support stand 22. The inner cylinder blocks passing of radiant heat from the external heating means through the central part. The mold support stand is elevated/lowered by an elevating/lowering apparatus, and the molds can be attached/detached to/from the space. Molten metal can be poured into the molds at an elevation position. The elevating/lowering apparatus lowers the molds into which molten metal has been poured, and the molten metal can be unidirectionally solidified. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a unidirectional solidification casting apparatus for producing a unidirectional solidification (columnar crystal, single crystal) precision casting product.

  Blades and the like used in aircraft and power generation turbines are precision parts and require high-temperature strength, and there is a unidirectional solidification casting apparatus as an apparatus for producing high-strength and precision parts.

  A unidirectional solidification casting apparatus injects molten metal (hot water) such as nickel alloy into a mold, and the mold is gradually moved from a heating area to a cooling area in a vacuum vessel to grow a continuous single crystal in the moving direction. It is solidified. By making the internal structure a single crystal, a high-strength cast product can be obtained even at high temperatures.

  As a conventional unidirectional solidification casting apparatus, there is one disclosed in Patent Document 1.

  A heating chamber having a lower opening is provided in the vacuum container, and the heating chamber can store a mold, and the mold is placed on a cooling plate that also serves as a lift, and is concentrically placed on the cooling plate. A required number of runners installed at equal intervals and extending radially from the gate communicate with the mold. Also, the mold is removed from the lower side of the heating chamber by raising and lowering the lifting platform.

  The heating chamber is a heating region, a cooling ring is provided below the opening, and the cooling region is provided below the opening as a heating / cooling boundary. In the heating area, the mold is heated from the surroundings by radiant heat, and in the cooling area, the mold is cooled from the surroundings by a cooling ring.

  In a state where the mold stored in the heating chamber is heated to a predetermined temperature, hot water is poured from the pouring gate, and hot water is filled into the mold through the runner.

  The elevator is lowered at a low speed, and the mold is drawn below the heating / cooling boundary, so that it is cooled by the cooling ring and gradually cooled while growing a single crystal from the drawn part. ing.

  As described above, the mold is heated by radiant heat from the surroundings in the heating chamber, and is cooled from the outer periphery in the cooling region beyond the boundary. In order to slowly cool and grow columnar crystals or single crystals, it is preferable that the boundary between the heating region and the cooling region is clear and that no temperature distribution difference occurs in the radial direction.

  However, since the heating chamber is loaded and unloaded through the opening, there is heat radiation from the opening. For this reason, the inside of the part which moved to the cooling area | region of the casting_mold | template will be in the state heated by the thermal radiation from opening. For this reason, the boundary between the heating region and the cooling region becomes unclear and a temperature difference is generated in the radial direction, which is an impediment to columnar crystal or single crystal growth.

JP 2002-144019 A

  In view of such circumstances, the present invention provides a unidirectional solidification casting apparatus in which a boundary between a heating region and a cooling region is clear and a temperature difference in the radial direction is eliminated during heating and cooling. A device is provided.

  In the present invention, an inner cylinder is provided concentrically in the center of a cylindrical external heating means, a cylindrical space is formed between the inner cylinder and the external heating means, and a required number of molds are stored in the space. The mold is arranged circumferentially on a ring-shaped mold support base, the inner cylinder blocks radiant heat from the external heating means from penetrating through the center portion, and the mold support base is The mold can be moved up and down, the mold can be inserted into and removed from the space, and the mold can be poured in a raised position, and the lifting device can lower the poured mold and solidify the molten metal in one direction. The unidirectional solidification casting apparatus.

  The present invention also relates to a unidirectional solidification casting apparatus in which a heating element is provided inside the inner cylinder to constitute an internal heating means.

  In the present invention, an external cooling means is provided downward from the external heating means, a lower inner cylinder is provided downward from the inner cylinder, and a heating region is provided above the lower end of the external heating means as a boundary. A cooling region is formed, and the lower inner cylinder relates to a unidirectional solidification casting apparatus configured to block radiation heat from the heating region from reaching the cooling region.

  Further, the present invention relates to a unidirectional solidification casting apparatus in which an internal cooling coil for circulating a cooling medium is provided inside the lower inner cylinder, and an internal cooling means is configured.

  Furthermore, in the present invention, the upper end of the mold is communicated with a ring-shaped runner, a pouring gate is provided at a required position of the runner, and pouring into a plurality of molds is possible through the pouring gate and the runner. The present invention relates to a directional solidification casting apparatus.

  According to the present invention, an inner cylinder is provided concentrically at the center of the cylindrical external heating means, a cylindrical space is formed between the inner cylinder and the external heating means, and a required number of molds are formed in the space. The mold is disposed on the ring-shaped mold support base in the circumferential direction, the inner cylinder blocks the radiant heat from the external heating means from penetrating through the center portion, and the mold support is supported by the lifting device. The platform can be moved up and down, the mold can be inserted into and removed from the space, and the mold can be poured at a raised position. The lifting device can lower the poured mold and solidify the molten metal in one direction. Since it is possible, the inner cylinder functions as a radiant heat blocking means. Further, since the mold is arranged in a cylindrical space, it is easy to increase the number of molds to be arranged by increasing the diameter of the cylinder, and the productivity can be improved.

  According to the present invention, since the heating element is provided inside the inner cylinder and the internal heating means is configured, the mold can be heated from inside and outside, the heating time of the mold is shortened, and the productivity is improved. Moreover, it becomes possible to cope with an increase in size of the unidirectional solidification casting apparatus. In addition, the temperature distribution in the radial direction is eliminated.

  Further, according to the present invention, an external cooling means is provided downward from the external heating means, a lower inner cylinder is provided downward from the inner cylinder, and a heating region is formed upward with the lower end of the external heating means as a boundary. The cooling region is formed below, and the lower inner cylinder is configured to block the radiant heat from the heating region from reaching the cooling region, so that the boundary between the heating region and the cooling region becomes clear and the diameter Since the directional temperature distribution is eliminated, it is easy to achieve unidirectional solidification.

  Further, according to the present invention, the inner cooling coil for circulating the cooling medium is provided inside the lower inner cylinder, and the inner cooling means is configured. Therefore, cooling can be performed from the inside and outside of the mold in the cooling region, and the temperature distribution in the radial direction is increased. Since this is eliminated, it is easy to achieve unidirectional solidification.

  Furthermore, according to the present invention, the upper end of the mold is communicated with a ring-shaped runner, a pouring gate is provided at a required position of the runner, and pouring can be performed on a plurality of molds via the pouring gate and the runner. Therefore, even when there is an obstacle in the center, pouring can be performed, and the length of the runner per mold does not change even when the number of molds is increased. In addition to being able to reduce the number, the excellent effect of being able to cope with an increase in size of the unidirectional solidification casting apparatus is exhibited.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

  1 and 2 schematically show an example of a unidirectional solidification casting apparatus in which the present invention is implemented.

  In the figure, reference numeral 1 denotes a vacuum vessel. A vacuum exhaust device (not shown) is connected to the vacuum vessel 1 so that the inside of the vacuum vessel 1 can be evacuated.

  The required height of the vacuum vessel 1 is provided with a ring-shaped shelf plate 3 having a circular opening 2 formed in the center, and a cylinder in which heating means and cooling means are integrated with the ring-shaped shelf plate 3. A heating / cooling unit 4 is installed. The heating / cooling unit 4 will be described below.

  A support cylinder 5 also serving as a cooling plate is provided concentrically with the opening 2, and a ring-shaped outer shielding flange 6 is provided at the upper end of the support cylinder 5, and the same as the support cylinder 5 via the outer shielding flange 6. A diameter outer cylinder 7 is provided on the same center line as the support cylinder 5. The outer shielding flange 6 projects to both the inner diameter side and the outer diameter side of the support cylinder 5. Here, the support tube 5 is made of heat-resistant steel such as stainless steel having a relatively high thermal conductivity, and the outer shielding flange 6 is made of carbon or the like having high radiation characteristics. Carbon with high radiation characteristics is used.

  An inner cylinder 8 is disposed inside the outer cylinder 7 concentrically with the outer cylinder 7, and the outer cylinder 7 and the inner cylinder 8 form a double cylinder structure. The outer cylinder 7 and the inner cylinder A space 10 is formed between the two. A ceiling plate 11 is provided at the upper ends of the outer cylinder 7 and the inner cylinder 8, the inner cylinder 8 is supported by the ceiling plate 11, and the space 10 is closed at the upper end by the ceiling plate 11.

  A hollow hole 12 having the same diameter as the inner diameter of the inner cylinder 8 is formed at the center of the ceiling plate 11. A lower inner cylinder 14 is connected to the lower side of the inner cylinder 8 via an inner shielding flange 13. The inner shielding flange 13 has a ring shape in the drawing, but may be a solid disk. Further, the lower end of the lower inner cylinder 14 is closed, but may be opened.

  The material of the inner cylinder 8 is carbon as in the outer cylinder 7, and the lower inner cylinder 14 is made of stainless steel, like the support cylinder 5, and the ceiling plate 11 is made of stainless steel. Steel or the like is used, and carbon or the like is used for the inner shielding flange 13.

  A heating coil that is a heating element, such as an external induction heating coil 15, is provided on the outer peripheral side of the outer cylinder 7, and a heating coil that is a heating element, such as the internal induction heating coil 16, is provided on the inner peripheral side of the inner cylinder 8. The external induction heating coil 15 and the internal induction heating coil 16 are connected to a high frequency power source (not shown), respectively, and can supply high frequency power independently. The outer cylinder 7 and the external induction heating coil 15 constitute an external heating means 9, and the inner cylinder 8 and the internal induction heating coil 16 constitute an internal heating means 19.

  The external induction heating coil 15 and the internal induction heating coil 16 may be resistance heating coils.

  An outer cooling coil 17 is provided on the outer peripheral side of the upper end portion of the support cylinder 5, and an inner cooling coil 18 is provided on the inner side of the lower inner cylinder 14. Each of the outer cooling coil 17 and the inner cooling coil 18 is a hollow tube, and is connected to a cooling source (not shown). The outer cooling coil 17 and the inner cooling coil 18 are connected to a cooling source by a cooling source. A refrigerant such as water is circulated. The support cylinder 5 and the outer cooling coil 17 constitute an external cooling means 28, and the lower inner cylinder 14 and the inner cooling coil 18 constitute an internal cooling means 29.

  The inner cylinder 8 and the lower inner cylinder 14 also function as radiant heat shielding means for blocking the radiant heat from the external heating means 9 from penetrating through the central portion.

  A ring-shaped mold support 22 (made of copper) is supported on a lift base 21 that is lifted and lowered by a lift (not shown) via a plurality of (two in the drawing) support columns 20. The mold 23 is erected on the circumference, a ring-shaped runner 24 is provided over the upper end of the mold 23, and the runner 24 communicates with the inside of the mold 23. A pouring gate 25 is provided at a required position of the runner 24, and a pouring window 26 is formed at a position corresponding to the pouring gate 25 of the ceiling plate 11. The hot pouring window 26 can be opened and closed by a lid (not shown). It has become.

  When the mold support 22 is raised by a lifting device (not shown), the mold support base 22 is brought into contact with or substantially in contact with the lower surface of the outer shielding flange 6.

  Hereinafter, the operation of the unidirectional solidification casting apparatus according to the present invention will be described.

  With the mold support 22 raised, high frequency power is supplied to the external induction heating coil 15 and the internal induction heating coil 16, the outer cylinder 7 and the inner cylinder 8 are heated, and the outer cylinder 7, The mold 23 is heated through the inner cylinder 8. The mold 23 is heated from the inside and outside by the external heating means 9 and the internal heating means 19 to increase the rate of temperature rise and shorten the heating time. Further, the temperature difference between the inside and outside, that is, the temperature distribution in the radial direction is eliminated.

  When the mold 23 reaches a predetermined temperature, for example, a hot water temperature, the mold 23 is maintained for a predetermined time, the hot water injection window 26 is opened, and hot water is injected from the pouring gate 25. Hot water is filled in each mold 23 through the runner 24. Cooling water is circulated through the outer cooling coil 17 and the inner cooling coil 18, and the upper part of the support cylinder 5 and the lower inner cylinder 14 are cooled. Is a cooling region.

  When pouring is completed, the hot water injection window 26 is closed by a lid, and the lowering of the mold 23 (drawing of the mold) is started by an elevator device (not shown). The rate of descent is set so as to be a rate of temperature reduction that solidifies in one direction when the hot water solidifies.

  When the mold 23 is lowered, the mold 23 moves from the lower side of the mold 23 to a cooling region with the outer shielding flange 6 as a boundary, and is gradually cooled.

  As described above, since the lower inner cylinder 14 protrudes downward from the inner cooling coil 18, the upper portion of the mold 23 with the outer shielding flange 6 and the inner shielding flange 13 as a boundary is the external guide. A portion that has been heated from both the outer periphery and the inner periphery by the heating coil 15 and the internal induction heating coil 16 and has moved to the cooling region of the mold 23 is moved from the outer periphery by the outer cooling coil 17 and the inner cooling coil 18. Cooled from both the inner circumference.

  Further, the lower inner cylinder 14 protruding to the cooling position blocks the radiant heat from the outer cylinder 7 that reaches the mold 23 through the center, and the inner portion of the outer shielding flange 6 is the outer cylinder. 7 to block the heat radiation to the outer cooling coil 17 portion. Further, radiant heat from the inner cylinder 8 to the mold 23 is blocked by the inner shielding flange 13.

  Accordingly, a cooling region is formed on the lower side that is not affected by the heating region or very little affected by the outer shielding flange 6 and the inner shielding flange 13, and there is a clear boundary between the heating region and the cooling region. It is formed.

  Further, in the cooling region, the inner cooling coil 18 also cools from the inside, and the temperature distribution in the radial direction is made uniform.

  It should be noted that the effect of blocking radiant heat by the inner shielding flange 13 and the lower inner cylinder 14 is clear, and the internal induction heating coil 16 and the inner cooling coil 18 can be omitted.

  Further, since the inner cylinder 8 is formed and the mold 23 is disposed around the inner cylinder 8, the size can be increased by enlarging the inner cylinder. Since 23 is heated and cooled from the outside and from the inside, the state of heating and cooling does not change, and even if the runner 24 is enlarged in diameter, the runner 24 is supported and supported by the mold 23. The intervals can be the same or the same. Further, the length of the runner per mold can be the same even when the mold is enlarged, and the amount of hot water used can be saved.

  Therefore, the number of molds 23 to be installed can be increased, productivity can be improved, and production cost per casting can be reduced.

1 is a schematic cross-sectional perspective view showing an embodiment of the present invention. It is an expanded sectional view of the heating / cooling unit in the embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Vacuum vessel 4 Heating / cooling unit 6 Outer shielding flange 7 Outer cylinder 8 Inner cylinder 9 External heating means 11 Ceiling plate 13 Inner shielding flange 14 Lower inner cylinder 15 External induction heating coil 16 Internal induction heating coil 17 Outer cooling coil 18 Internal cooling Coil 19 Internal heating means 22 Mold support 23 Mold 24 Runway 25 Spout 26 Hot water injection window 28 External cooling means 29 Internal cooling means

Claims (5)

  An inner cylinder is provided concentrically at the center of the cylindrical external heating means, a cylindrical space is formed between the inner cylinder and the external heating means, and a required number of molds can be stored in the space. The mold is arranged in a circumferential direction on a ring-shaped mold support base, the inner cylinder blocks the radiant heat from the external heating means from penetrating through the center part, and the mold support base is lifted and lowered by a lifting device, The mold can be inserted into and removed from the space, and the mold can be poured into a raised position, and the lifting device can lower the poured mold and solidify the molten metal in one direction. Unidirectional solidification casting equipment.   The unidirectional solidification casting apparatus according to claim 1, wherein a heating element is provided inside the inner cylinder to constitute an internal heating means.   An external cooling means is provided downward from the external heating means, a lower inner cylinder is provided downward from the inner cylinder, and a heating area is formed above and a cooling area is formed below the lower end of the external heating means as a boundary. The unidirectional solidification casting apparatus according to claim 1, wherein the lower inner cylinder is configured to block radiation heat from the heating region from reaching the cooling region.   The unidirectional solidification casting apparatus according to claim 1, wherein an inner cooling coil for circulating a cooling medium is provided inside the lower inner cylinder to constitute an internal cooling means.   The one-way solidification of the said mold which connected the upper end of the said mold with the ring-shaped runway, provided the pouring gate in the required position of this runway, and was able to pour into several casting_mold | templates via this pouring gate and the said runner. Casting equipment.

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