JP5124163B2 - Casting equipment - Google Patents

Description

  The present invention relates to a casting apparatus used in a V process casting method.

  The V Process (Vacuum Sealed Molding Process) casting method is also called a reduced pressure mold making method, and is one of the methods classified into sand mold methods in which casting is performed using a sand mold. Unlike the conventional sand mold method, this is a method in which a binder is not used in foundry sand, a resinous film is used as a sealing material, and a mold is formed by utilizing the pressure difference between the film inside and outside air. Its features include not only a wide range of applications from small products to large products, but also the ability to handle complex shapes and thin shapes, as well as other casting methods in terms of dimensional accuracy and aesthetics of the casting surface. The point which is excellent and the point which mold release is easy and can recycle casting sand etc. are mentioned. The V process casting method is one of the casting methods widely used in the current industry.

  Here, as an example of a conventional V process casting method, there is a casting method described in Patent Document 101. First, as shown in FIG. 13 (a), a forming surface 103 having a forming shape 102 is formed on the surface of the original member 101, and an exhaust pipe 104 is inserted into the original member 101. The extraction pipe 104 and the molding surface 103 are communicated with each other through a large number of communication holes (not shown). While the shielding member 105 such as a thin synthetic resin film is heated on the molding surface 103 of the original member 101, the shielding member 105 is vacuum-sucked by suction through the air extraction pipe 104 of the original member 101, and the shielding member 105 is molded. Vacuum-formed to the same shape as 102 and adheres. Next, as shown in FIG. 13 (b), the frame body 106 having the contact surface opened is brought into contact with the molding surfaces 103 on both sides, and the heat-resistant particulate material 111 is blown or poured into the frame body 106 from the supply port 107. Fill. Next, the supply port 107 is sealed with a lid 112, the air in the frame body 106 is evacuated from the air extraction port 108 provided with the filter 109, and the inside of the frame body 106 is set to a negative pressure, that is, the heat resistant particulate matter 111 When a negative pressure is applied between the particles, the shielding member 105 is pressed against the heat-resistant particulate material 111 side of the frame body 106 by the external air pressure. Since the heat resistant particulate matter 111 is filled in the frame body 106, the volume inside the frame body 106 does not change, and the heat resistant particulate matter 111 is pressed by the external pressure via the shielding member 105, Relative movement between each heat-resistant particulate material 111 is prevented. Therefore, as shown in FIG. 13C, the shape of the shielding member 105 is maintained without being deformed from the molded shape of the original member even after the frame body 106 is detached from the original member 101, thereby forming a mold. The cavity 113 is formed by combining the frame pairs 106 on both sides.

JP 47-38727 A

  The V process casting method is currently introduced in various industries in Japan and abroad because of its excellent characteristics. However, problems caused by the configuration of the casting apparatus used for the casting method, particularly the mold (sand mold), have been pointed out. In other words, the sand mold used in the V process casting method, as described above, presses the shielding member against the heat resistant particulate matter side by the external pressure by making the negative pressure between the particles of the heat resistant particulate matter (silica sand etc.). Thus, the relative movement between the respective heat-resistant particulates is prevented, and is formed as a mold. Therefore, because the sand mold is mainly composed of heat-resistant particulate matter and air intervening between each particle, when casting, cooling of the cast product after hot molten metal is poured into the cavity Was unavoidable by heat conduction and heat dissipation of the sand forming the sand mold. As a result, there is a problem that the cooling efficiency is poor and it takes a long time to release the mold, and the production capacity cannot be increased.

  On the other hand, as a request from the industry, it has been required to manufacture a cast product having higher strength (tensile strength and the like) by the V process casting method.

  The present invention has been made in view of the above circumstances, and is a casting apparatus used in a V process casting method, which can promote cooling of a cast product and is a time until mold release is possible as compared with a conventional apparatus. An object of the present invention is to provide a casting apparatus capable of improving the production capacity of a product by reducing the length of the product and improving the strength of the cast product.

  The present invention solves the above-described problems by the solving means described below.

  A casting apparatus according to the present invention is a casting apparatus used in a V process casting method, wherein a molding film is in close contact with a surface on which a cavity is formed, and a protective film is in close contact with an outer surface of the mold, and is molded with foundry sand. A sand mold including an upper mold and a lower mold; a decompression device that depressurizes the inside of the sand mold; and a plurality of air supply pipes that communicate between the outside and the inside of the sand mold. The film is made to penetrate the film and extend to the outside of the sand mold, and the other end side is disposed so as to reach the vicinity of the cavity without penetrating the molded film.

  In addition, the through portion through which the air supply pipe penetrates the protective film is formed such that an outer peripheral portion of the air supply pipe and the protective film are in close contact with each other.

  Further, the air supply pipe is characterized in that a tip end portion in the vicinity of the cavity is formed in a tapered shape.

  The casting apparatus according to the present invention is a casting apparatus used in the V process casting method, in which a molding film is in close contact with a surface on which a cavity is formed, and a protective film is in close contact with an outer surface of the mold, and molding is performed with foundry sand. A sand mold having an upper mold and a lower mold, a decompression device that depressurizes the inside of the sand mold, and a plurality of heat radiating members that communicate between the outside and the inside of the sand mold, and the heat radiating member has one end side While passing through the protective film and extending to the outside of the sand mold, the other end side is arranged to reach the vicinity of the cavity without penetrating the molded film.

  The heat dissipating member is made of a metal material.

  The casting apparatus according to the present invention is a casting apparatus used in the V process casting method, in which a molding film is in close contact with a surface on which a cavity is formed, and a protective film is in close contact with an outer surface of the mold, and molding is performed with foundry sand. A sand mold having an upper mold and a lower mold, and a pressure reducing device for depressurizing the inside of the sand mold, wherein the sand mold is formed in the vicinity of the cavity by cast water containing water. .

  Further, the sand mold is characterized in that the vicinity of the cavity is formed by foundry sand having a particle size larger than that of the foundry sand other than the vicinity of the cavity.

  According to the first aspect, the air supplied from the outside of the sand mold to the vicinity of the cavity through the air supply pipe is sucked into the suction pipe while depriving the heat in the vicinity of the cavity due to the heat of the molten metal to be poured. Therefore, the cooling in the vicinity of the cavity is promoted, and as a result, the cooling of the cast product can be promoted. As a result, an effect of shortening the time until mold release is possible as compared with the conventional apparatus is produced, and the production capacity of the product can be improved. Further, since the cast product can be rapidly cooled as compared with the conventional apparatus, the strength (tensile strength, etc.) of the cast product can be improved.

  According to the second aspect of the present invention, the air supply from the air supply pipe is obstructed by the suction of the air into the sand mold in the reduced pressure state by forming the outer peripheral portion of the air supply pipe and the protective film in close contact with each other. It becomes possible to solve the problem of being released and the problem of releasing the inside of the sand mold to the atmosphere.

  According to the third aspect, it is possible to improve “with sand” at the tip of the air supply pipe.

  According to the fourth aspect, the heat in the vicinity of the cavity, which is at a high temperature due to the heat of the molten metal to be poured, is absorbed by the heat radiating member made of a metal material having high heat conductivity, and extends to the outside of the sand mold. Since heat is mainly dissipated in the portion, cooling in the vicinity of the cavity is promoted, and as a result, cooling of the cast product can be promoted. As a result, an effect of shortening the time until mold release is possible as compared with the conventional apparatus is produced, and the production capacity of the product can be improved. Further, since the cast product can be rapidly cooled as compared with the conventional apparatus, the strength (tensile strength, etc.) of the cast product can be improved.

  According to the fifth aspect, since the heat dissipating member is made of a metal material, it is possible to improve the heat transfer property, and therefore it is possible to further improve the efficiency of heat absorption and heat dissipation.

  According to the sixth aspect, the heat in the vicinity of the cavity, which is at a high temperature due to the heat of the molten metal to be poured, is absorbed as the heat of vaporization for evaporating the water intervening around the foundry sand, and by the suction pipe. Since it is sucked together with air and radiated to the outside of the sand mold, cooling of the area near the cavity is promoted, and as a result, cooling of the cast product can be promoted. As a result, an effect of shortening the time until mold release is possible as compared with the conventional apparatus is produced, and the production capacity of the product can be improved. Further, since the cast product can be rapidly cooled as compared with the conventional apparatus, the strength (tensile strength, etc.) of the cast product can be improved.

  According to claim 7, when the heat in the vicinity of the cavity that is at a high temperature due to the heat of the molten metal to be poured is sucked together with the air inside the sand mold by the suction pipe and radiated to the outside of the sand mold, In particular, since the particle size of the foundry sand disposed in the cavity vicinity region that is high temperature is large, the fluidity of the air that has absorbed heat in the cavity vicinity region can be improved, and cooling of the cavity vicinity region is promoted. It will be. As a result, cooling of the cast product can be promoted. As a result, an effect of shortening the time until mold release is possible as compared with the conventional apparatus is produced, and the production capacity of the product can be improved. Further, since the cast product can be rapidly cooled as compared with the conventional apparatus, the strength (tensile strength, etc.) of the cast product can be improved.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic view showing an example of a casting apparatus 1 according to an embodiment of the present invention. FIG. 2 is a cross-sectional view taken along line A-A ′ of FIG. 1. FIG. 3 is an enlarged view of a portion X in FIG. FIG. 4 is a schematic diagram showing the configuration of the casting apparatus 1 according to the second embodiment of the present invention. FIG. 5 is a schematic view showing the configuration of the casting apparatus 1 according to the third embodiment of the present invention. 6 is a cross-sectional view taken along the line B-B ′ of FIG. 5. FIG. 7 is an enlarged view of a portion Y in FIG. FIG. 8 is a schematic view showing a configuration of a casting apparatus 1 according to the fourth embodiment of the present invention. 9 is a cross-sectional view taken along the line C-C ′ of FIG. 8. FIG. 10 is a schematic diagram showing a configuration of a casting apparatus 1 according to the fifth embodiment of the present invention. 11 is a cross-sectional view taken along the line D-D ′ of FIG. 10.

First, an outline of a general V process casting method will be described with reference to FIG.
As shown in FIG. 12A, the molded film 11 is heated and softened by the heater 61 and placed on the model surface 63. Here, the model 62 is mounted on a hollow surface plate 64 and provided with a large number of small holes 66 for film adsorption reaching the hollow chamber 65 from the surface (model surface 63). The molded film 11 preferably has a high elongation rate and a high plastic deformation rate. Examples thereof include an ethylene vinyl acetate copolymer resin film, a polyethylene film, a vinyl chloride film, a polypropylene film, and a polyvinyl alcohol film. used.

  Next, as shown in FIG. 12B, the pressure of the hollow chamber 65 is reduced, and air is sucked from the film adsorption small holes 66, thereby bringing the molded film 11 into close contact with the model surface 63. Thereafter, the mold frame 15 including the suction pipe 16 is attached to the upper part of the model 62.

  Next, as shown in FIG. 12 (c), the mold frame 15 is filled with the foundry sand 5 whose particle size has been adjusted while applying vibration. After filling, the sand on the upper surface is smoothed, and the upper surface (hereinafter referred to as “mold outer surface 13”) is covered with the protective film 12. The casting sand 5 is, for example, quartz sand, steel shot, zircon sand, etc., and a dry sand containing no caking additive is used.

  Next, as shown in FIG. 12 (d), the inside of the mold frame 15 is decompressed to cure the sand mold (here, the upper mold 3). Next, air is introduced into the hollow chamber 65 of the model 62 to release the adsorption of the molded film 11 to the model surface 63, and then the upper mold 3 is pulled upward to release the mold. Here, the molded film 11 adheres to a surface on which the cavity 6 is formed (hereinafter referred to as “cavity forming surface 7”).

  Next, as shown in FIG. 12E, the upper mold 3 and the lower mold 4 formed by the same process as described above are combined to constitute the sand mold 2. Molten metal is poured into the cavity 6 inside the sand mold 2 while the upper mold 3 and the lower mold 4 are respectively decompressed. At this time, the molded film 11 is dissolved.

  Next, as shown in FIG. 12 (f), after the molten metal is cooled, it is solidified to a state where it can be taken out as a product (cast product 8), and then the decompression of the upper mold 3 and the lower mold 4 is released to release the atmosphere. Since the foundry sand 5 of the sand mold 2 returns to the fluidized state, the cast product 8 can be taken out. The foundry sand 5 can be reused after cooling.

Next, the configuration of the casting apparatus according to the present invention will be described.
As shown in FIG. 1, the casting apparatus 1 is formed by molding sand 5 with a molding film 11 in close contact with a surface (cavity forming surface 7) on which a cavity 6 is formed, and a protective film 12 in close contact with a mold outer surface 13. The sand mold 2 including the upper mold 3 and the lower mold 4, a decompression device 18 that decompresses the inside of the sand mold 2, and a plurality of air supply pipes 21 that communicate the outside and the inside of the sand mold 2 are provided. Here, the method of forming the sand mold 2 including the upper mold 3 and the lower mold 4 is the same as the method described in FIGS. 12 (a) to 12 (e).

  As shown in FIGS. 1 to 3, the casting apparatus 1 is different from the conventional casting apparatus in that it includes a plurality of air supply pipes 21 that communicate the outside and the inside of the sand mold 2. A method of providing the air supply pipe 21 by supporting it on the beam of the mold frame 15 or the suction pipe 16 is conceivable. As another installation method, a method in which the sand mold 2 is formed and then inserted from the outside and supported by the foundry sand 5 is also conceivable.

  The air supply pipe 21 penetrates the protective film 12 at one end side (tip portion 22) and extends to the outside of the sand mold 2, and the other end side (tip portion 23) does not pass through the molded film 11 and the cavity 6 It reaches to the vicinity of and arranges. In addition, the supply pipe | tube 21 can consider the structure provided in both the upper mold | type 3 and the lower mold | type 4, and the structure provided only in any one. Further, a member (such as a mesh filter) for preventing the foundry sand 5 from entering the inside of the air supply pipe 21 is attached to the distal end portion 23 as necessary.

  As an operation of the above configuration, the pressure reducing device 18 is operated, and the air inside the sand mold 2 is sucked from the plurality of air suction holes 17 opened on the outer peripheral surface of the suction pipe 16 inserted into the sand mold 2. The sand mold 2 is depressurized. Along with this, air outside the sand mold 2 is introduced into the sand mold 2 from the tip section 23 through the air supply pipe 21 in which the tip section 22 is extended to the outside of the sand mold 2 (FIG. 3).

  In the conventional V process casting method, since there is a step of depressurizing the inside of the sand mold, it was considered that taking air from the outside of the sand mold into the sand mold was one of the most prohibited acts. . Actually, in the casting apparatus 1 having the above-described configuration, the introduction of external air into the sand mold 2 to the extent that the decompression capacity of the decompression apparatus 18 is exceeded causes an effect similar to that of the atmosphere release. Therefore, it is not established as a casting apparatus used in the V process casting method.

  However, the following remarkable effects can be achieved by adjusting the sand mold internal pressure in the reduced pressure region that is not released to the atmosphere and causing the air introduction action described above. That is, according to the conventional casting apparatus, since the cooling of the molten metal is only due to the heat conduction of the foundry sand 5, it takes a long time to cool, and the production capacity of the cast product 8 cannot be increased. However, since the air 26 supplied to the vicinity of the cavity 6 from the outside of the sand mold 2 is sucked into the suction pipe 16 while taking away the heat in the vicinity of the cavity 6 due to the heat of the molten metal poured, Cooling in the vicinity of the cavity 6 is promoted, and as a result, cooling of the casting 8 can be promoted. As a result, an effect of shortening the time until mold release is possible as compared with the conventional apparatus is produced, and the production capacity of the product can be improved.

  Here, FIG. 14 shows an example of numerical data achieved by the casting apparatus 1 according to the present embodiment, and proves the effectiveness of the present invention. In this experiment, the result that the cooling time can be shortened by 50% compared with the conventional apparatus was obtained. This is merely an example, and by optimally setting the components such as the output of the decompression device 18, the number / arrangement of the suction pipes 16, the number / arrangement of the air suction holes 17, the number / arrangement of the air supply pipes 21, etc. Further, the cooling time can be further shortened.

  Furthermore, as a result of the rapid cooling of the cast product 8, the strength (such as tensile strength) of the cast product 8 can be improved. Here, Table 1 shows an example of numerical data achieved by the casting apparatus 1 according to the present embodiment. In this embodiment, an improvement of 10% compared to the conventional case is possible. Similar to the above, the strength can be further improved by optimally setting the components of the casting apparatus 1.

  In addition, it is preferable that the through portion 25 through which the air supply pipe 21 penetrates the protective film 12 is formed such that the outer peripheral portion of the air supply pipe 21 and the protective film 12 are in close contact with each other.

  If the outer peripheral portion of the air supply pipe 21 and the protective film 12 are not in close contact with each other and there is a gap, air is sucked into the sand mold 2 in a decompressed state from the gap, and the air supply pipe 21 is moved to the vicinity of the target cavity 6. Air supply will be hindered. Furthermore, there is a possibility that the voids release the inside of the sand mold 2 to the atmosphere. However, such a problem can be solved by a configuration in which the outer peripheral portion of the air supply pipe 21 and the protective film 12 are formed in close contact with each other in the through portion 25.

  As a second embodiment, as shown in FIG. 4, the air supply pipe 21 has a configuration in which a tip end portion 23 ′ in the vicinity of the cavity is formed in a tapered shape.

  With this configuration, an effect of improving “sand” at the tip 23 ′ of the air supply pipe 21 is produced. Here, “with sand” means sand necessary for mold holding.

Next, a third embodiment of the casting apparatus according to the present invention will be described.
As shown in FIG. 5, the casting apparatus 1 includes an upper mold 3 and a lower mold 4 that are formed by casting sand 5 with a molding film 11 in close contact with the cavity forming surface 7 and a protective film 12 in close contact with the outer surface 13 of the mold. , A pressure reducing device 18 that depressurizes the inside of the sand mold 2, and a plurality of heat radiation members 31 that communicate the outside and the inside of the sand mold 2. Here, the method of forming the sand mold 2 including the upper mold 3 and the lower mold 4 is the same as the method described in FIGS. 12 (a) to 12 (e).

  The casting apparatus 1 is different from the first embodiment shown in FIGS. 1 to 3 in that a plurality of heat radiating members 31 are provided instead of the plurality of air supply pipes 21. A method of providing the heat radiating member 31 by supporting it on the beam of the mold frame 15 or the suction pipe 16 is conceivable. In addition, the method of inserting from the outside after forming the sand mold 2 is also considered.

The heat radiating member 31 is made of a metal material having high heat conductivity, and is preferably formed in a shape having a larger surface area than a flat plate. An example is a plate-like, tubular or columnar member provided with fins, or a combination thereof. Further, one end side (tip portion 32) penetrates the protective film 12 and extends to the outside of the sand mold 2, and the other end side (tip portion 33) does not penetrate the molding film 11 and reaches the vicinity of the cavity 6. Arrange to reach. Here, the structure provided in both the upper mold | type 3 and the lower mold | type 4 and the structure provided only in any one can be considered for the thermal radiation member 31. FIG.
In addition, the heat radiating member 31 may be configured by a tubular member (for example, a metal pipe), and the refrigerant may be circulated therein. Furthermore, one end side (tip portion 32) of the heat radiating member 31 may be disposed in the vicinity of the suction pipe 16 without penetrating the protective film 12, and heat may be sucked into the suction pipe 16.

  As an operation of the above-described configuration, according to the conventional casting apparatus, the molten metal is cooled only by the heat conduction of the foundry sand 5, so that it takes a long time to cool and the production capacity of the cast product 8 can be increased. could not. However, according to the casting apparatus 1 according to the present invention, the heat in the vicinity of the cavity 6 that is high due to the heat of the molten metal to be poured is absorbed by the heat radiating member 31 made of a metal material having high heat conductivity. At the same time, since heat is mainly dissipated in the portion extending to the outside of the sand mold 2, cooling in the vicinity of the cavity 6 is promoted, and as a result, cooling of the cast product 8 can be promoted. As a result, an effect of shortening the time until mold release is possible as compared with the conventional apparatus is produced, and the production capacity of the product can be improved. Furthermore, you may provide the mechanism in which the part extended to the exterior of the sand mold 2 in the thermal radiation member 31 is forcedly air-cooled or water-cooled. Thereby, cooling of the casting 8 can be further promoted.

  Here, FIG. 15 shows an example of numerical data achieved by the casting apparatus 1 according to the present embodiment. In this experiment, the cooling time can be shortened by 20% compared with the conventional apparatus. This is merely an example, and the components such as the output of the decompression device 18, the number / arrangement of the suction pipes 16, the number / arrangement of the air suction holes 17, and the number / arrangement / area of the heat dissipating members 31 are optimally set. As a result, the cooling time can be further shortened.

  As described above, the strength can be improved by optimally setting the components of the casting apparatus 1.

  In addition, it is preferable that the penetration part 35 through which the heat radiating member 31 penetrates the protective film 12 is formed by closely attaching the outer peripheral part of the heat radiating member 31 and the protective film 12. This is because, if the outer peripheral portion of the heat radiating member 31 and the protective film 12 are not in close contact with each other and there is a gap, air is sucked into the sand mold 2 in a decompressed state from the gap to release the inside of the sand mold 2 to the atmosphere. This is because there is a risk of losing. However, such a problem can be solved by a configuration in which the outer peripheral portion of the heat dissipation member 31 and the protective film 12 are formed in close contact with each other in the through portion 35.

Next, a fourth embodiment of the casting apparatus according to the present invention will be described.
As shown in FIG. 8, the casting apparatus 1 includes an upper mold 3 and a lower mold 4 that are formed by molding sand 5 with a molding film 11 in close contact with the cavity forming surface 7 and a protective film 12 in close contact with the outer surface 13 of the mold. And a decompression device 18 for decompressing the inside of the sand mold 2. Here, the method of forming the sand mold 2 including the upper mold 3 and the lower mold 4 is the same as the method described in FIGS. 12 (a) to 12 (e).

  As shown in FIGS. 8 and 9, the casting apparatus 1 is different from a conventional casting apparatus in that the vicinity of the cavity 6 of the sand mold 2 is formed by the foundry sand 41 containing water. The range formed by the foundry sand 41 and the moisture content of the foundry sand 41 are set as appropriate. In addition, the structure provided in both the upper mold | type 3 and the lower mold | type 4 and the structure provided only in any one can be considered for the foundry sand 41 containing water.

  Since the conventional V process casting method has a step of reducing the pressure inside the sand mold, it is considered to be one of the most prohibited acts to use the foundry sand that contains water when forming the sand mold. It was. The reason for this is that when the sand mold is formed using the water-containing foundry sand, moisture is interposed between the particles of the foundry sand, and as a result, the suction of air inside the sand mold is inhibited, This is because it is difficult to reduce the pressure inside the sand mold. In the first place, there is also a problem that it is difficult to fill the foundry sand containing water into the cavity. Therefore, a sand mold formed by using a large amount of water-containing foundry sand is not suitable as a component of a casting apparatus used in the V process casting method.

  However, the following remarkable effects can be obtained by forming the sand mold 2 using the foundry sand 41 containing water in the vicinity of the cavity 6 while adjusting so as not to inhibit the air suction inside the sand mold. It becomes possible. That is, according to the conventional casting apparatus, since the cooling of the molten metal is only due to the heat conduction of the foundry sand 5, it takes a long time to cool, and the production capacity of the cast product 8 cannot be increased. However, according to the casting apparatus 1 according to the present invention, the heat in the vicinity of the cavity 6 that is high due to the heat of the molten metal to be poured is used as the heat of vaporization for vaporizing the water present around the foundry sand 41. Since the heat is absorbed and sucked together with the air inside the sand mold 2 by the suction pipe 16 and radiated to the outside of the sand mold 2, cooling in the vicinity of the cavity 6 is promoted, and as a result, cooling of the casting 8 can be promoted. It becomes possible. As a result, an effect of shortening the time until mold release is possible as compared with the conventional apparatus is produced, and the production capacity of the product can be improved. At first glance, such an effect gives the impression that it can be achieved in the same way other than the conventional V process casting method. However, it is difficult to obtain such an effect only by forming a sand mold using casting sand containing water in the periphery of the cavity. This is because there is no means for moving the evaporated water. As described above, the effect produced by forming the sand mold using the water-containing foundry sand is realized by a synergistic effect with the pressure reducing mechanism inside the sand mold in the V process casting method.

  Here, FIG. 16 shows an example of numerical data achieved by the casting apparatus 1 according to the present embodiment. In this experiment, the result that the cooling time can be shortened by 10% compared with the conventional apparatus was obtained. This is merely an example, and the configuration of the output of the decompression device 18, the number and arrangement of the suction pipes 16, the number and arrangement of the air suction holes 17, the range formed by the foundry sand 41, the moisture content of the foundry sand 41, etc. The cooling time can be further shortened by optimally setting the elements.

  Furthermore, as a result of the rapid cooling of the cast product 8, the strength (such as tensile strength) of the cast product 8 can be improved. Here, Table 2 shows an example of numerical data achieved by the casting apparatus 1 according to the present embodiment. In this embodiment, an improvement of 20% compared to the conventional case is possible. Similar to the above, the strength can be further improved by optimally setting the components of the casting apparatus 1. In addition, the casting apparatus according to the present embodiment has a higher strength improvement rate than the first to third embodiments described above, which enables rapid cooling of the molten metal more than those embodiments. Due to the fact that

Next, a fifth embodiment of the casting apparatus according to the present invention will be described.
As shown in FIG. 10, the casting apparatus 1 includes an upper mold 3 and a lower mold 4 which are formed by casting sand 5 with a molding film 11 in close contact with the cavity forming surface 7 and a protective film 12 in close contact with the outer surface 13 of the mold. And a decompression device 18 for decompressing the inside of the sand mold 2. Here, the method of forming the sand mold 2 including the upper mold 3 and the lower mold 4 is the same as the method described in FIGS. 12 (a) to 12 (e).

  As shown in FIGS. 10 and 11, the casting apparatus 1 is a foundry sand in which the vicinity of the cavity 6 of the sand mold 2 has a larger particle size than the foundry sand 52 (for example, No. 8 sand) in a portion other than the vicinity of the cavity. It differs from the conventional casting apparatus by the point formed by 51 (for example, No. 4 sand). The range formed by the foundry sand 51 and the particle size of the foundry sand 51 are set as appropriate. In addition, the said casting sand 51 can consider the structure provided in both the upper mold | type 3 and the lower mold | type 4, and the structure provided only in any one.

  As an operation of the above-described configuration, according to the conventional casting apparatus, the molten metal is cooled only by the heat conduction of the foundry sand 5, so that it takes a long time to cool and the production capacity of the cast product 8 can be increased. could not. However, according to the casting apparatus 1 according to the present invention, the heat in the vicinity of the cavity 6 that is at a high temperature due to the heat of the molten metal to be poured is sucked together with the air inside the sand mold 2 by the suction pipe 16 to be sand mold. (2) When the heat is radiated to the outside, the fluidity of the air that has absorbed heat in the vicinity of the cavity 6 is improved because the particle size of the foundry sand 51 disposed in the vicinity of the cavity 6 that is particularly high in temperature is large. As a result, cooling in the vicinity of the cavity 6 is promoted. As a result, it becomes possible to promote the cooling of the casting 8. As a result, an effect of shortening the time until mold release is possible as compared with the conventional apparatus is produced, and the production capacity of the product can be improved. In addition, the shape close | similar to a sphere is suitable for the foundry sand 51. FIG. The reason is that the effect of improving the fluidity of the surrounding air is produced, and the cooling is further promoted.

  Here, FIG. 17 shows an example of numerical data achieved by the casting apparatus 1 according to the present embodiment. In this experiment, the result that the cooling time can be shortened by 40% compared with the conventional apparatus was obtained. This is merely an example, and the configuration of the output of the decompression device 18, the number and arrangement of the suction pipes 16, the number and arrangement of the air suction holes 17, the range formed by the foundry sand 51, the particle size of the foundry sand 51, and the like. The cooling time can be further shortened by optimally setting the elements.

  Furthermore, as a result of the rapid cooling of the cast product 8, the strength (such as tensile strength) of the cast product 8 can be improved. Here, Table 3 shows an example of numerical data achieved by the casting apparatus 1 according to the present embodiment. In this embodiment, an improvement of 20% compared to the conventional case is possible. Similar to the above, the strength can be further improved by optimally setting the components of the casting apparatus 1.

  As described above, according to the casting apparatus according to the present invention, the cooling in the vicinity of the cavity is promoted, and as a result, the cooling of the cast product can be promoted. As a result, an effect of shortening the time until mold release is possible as compared with the conventional apparatus is produced, and the production capacity of the product can be improved. Furthermore, as a result of the rapid cooling of the cast product, the strength (such as tensile strength) of the cast product can be improved.

  Although the embodiments according to the present invention have been described above, the effects of promoting cooling and improving the strength can be synergistically increased by adopting a configuration in which the embodiments are combined.

It is the schematic which shows an example of the casting apparatus which concerns on embodiment of this invention. It is A-A 'sectional drawing of FIG. It is the X section enlarged view of FIG. It is the schematic which shows the structure of the casting apparatus which concerns on 2nd embodiment of this invention. It is the schematic which shows the structure of the casting apparatus which concerns on 3rd embodiment of this invention. FIG. 6 is a B-B ′ sectional view of FIG. 5. It is the Y section enlarged view of FIG. It is the schematic which shows the structure of the casting apparatus which concerns on 4th embodiment of this invention. It is C-C 'sectional drawing of FIG. It is the schematic which shows the structure of the casting apparatus which concerns on 5th embodiment of this invention. It is D-D 'sectional drawing of FIG. It is the schematic for demonstrating the general V process casting method. It is the schematic which shows an example of the casting apparatus which concerns on the conventional embodiment. It is a comparison figure explaining the effect by the casting device concerning the present invention. It is a comparison figure explaining the effect by the casting device concerning the present invention. It is a comparison figure explaining the effect by the casting device concerning the present invention. It is a comparison figure explaining the effect by the casting device concerning the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Casting apparatus 2 Sand mold 3 Upper mold 4 Lower mold 5 Foundry sand 6 Cavity 7 Cavity formation surface 11 Molded film 12 Protective film 13 Mold outer surface 16 Suction pipe 17 Air suction hole 18 Decompression apparatus 21 Supply pipe 25 Penetration part 29 From molten metal Heat 31 Heat-dissipating member 39 Heat conduction in heat-dissipating member 41 Water-containing foundry sand 51 Large-size foundry sand 52 Normal-size foundry sand

Claims (6)

A casting apparatus used in the V process casting method,
A sand mold comprising an upper mold and a lower mold formed of foundry sand, with a molded film closely attached to the surface on which the cavity is formed, and a protective film closely attached to the outer surface of the mold;
A decompression device for decompressing the inside of the sand mold;
A plurality of air supply pipes communicating the outside and the inside of the sand mold;
The air supply pipe is arranged so that one end side extends through the protective film to the outside of the sand mold, and the other end side reaches the vicinity of the cavity without penetrating the molding film. Casting equipment characterized. The casting apparatus according to claim 1, wherein a penetration portion through which the air supply pipe penetrates the protective film is formed such that an outer peripheral portion of the air supply pipe and the protective film are in close contact with each other. The casting apparatus according to claim 1 or 2, wherein the air supply pipe has a tip end portion in the vicinity of the cavity formed in a tapered shape. A casting apparatus used in the V process casting method,
A sand mold comprising an upper mold and a lower mold formed of foundry sand, with a molded film closely attached to the surface on which the cavity is formed, and a protective film closely attached to the outer surface of the mold;
A decompression device for decompressing the inside of the sand mold;
A plurality of heat dissipating members communicating the outside and the inside of the sand mold;
The heat dissipating member is arranged so that one end side penetrates the protective film and extends to the outside of the sand mold, and the other end side reaches the vicinity of the cavity without penetrating the molding film. Casting equipment characterized. The casting apparatus according to claim 4, wherein the heat radiating member is made of a metal material. The sand mold is of any one of claims 1-5, characterized in that the vicinity of the cavity by a large casting sand particle size than sand in the portion other than the vicinity of the cavity is formed Casting equipment.